vpruthi/doc-exports
1
0
Fork 0
forked from docs/doc-exports
Code Pull Requests Activity
doc-exports/docs/dws/dev/dws_04_0936.html
Lu, Huayi a24ca60074 DWS DEVELOPER 811 version 
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
Co-authored-by: Lu, Huayi <luhuayi@huawei.com>
Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
2023-01-19 13:37:49 +00:00

468 lines
111 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<a name="EN-US_TOPIC_0000001145894431"></a><a name="EN-US_TOPIC_0000001145894431"></a>
<h1 class="topictitle1">Developer Operations</h1>
<div id="body8662426"><div class="section" id="EN-US_TOPIC_0000001145894431__section5236926112310"><h4 class="sectiontitle">enable_light_colupdate</h4><p id="EN-US_TOPIC_0000001145894431__p72361726112312"><strong id="EN-US_TOPIC_0000001145894431__b2011513209113">Parameter description</strong>: Specifies whether to enable the lightweight column-store update.</p>
<p id="EN-US_TOPIC_0000001145894431__p9236226202310"><strong id="EN-US_TOPIC_0000001145894431__b44741056229">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p13236526132313"><strong id="EN-US_TOPIC_0000001145894431__b540139201819">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul823752613230"><li id="EN-US_TOPIC_0000001145894431__li4237122612319"><strong id="EN-US_TOPIC_0000001145894431__b998217114227">on</strong> indicates that the lightweight column-store update is enabled.</li><li id="EN-US_TOPIC_0000001145894431__li11237112619234"><strong id="EN-US_TOPIC_0000001145894431__b24381234112211">off</strong> indicates that the lightweight column-store update is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p123772632314"><strong id="EN-US_TOPIC_0000001145894431__b10699182711187">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b18699152716186">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s9b7f64f4f112450490c8c74b520cc915"><a name="EN-US_TOPIC_0000001145894431__s9b7f64f4f112450490c8c74b520cc915"></a><a name="s9b7f64f4f112450490c8c74b520cc915"></a><h4 class="sectiontitle">enable_fast_query_shipping</h4><p id="EN-US_TOPIC_0000001145894431__a68176f11af7249f48e67ee4b0782b562"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706161736">Parameter description</strong>: Specifies whether to use the distributed framework for a query planner.</p>
<p id="EN-US_TOPIC_0000001145894431__p8226203042311"><strong id="EN-US_TOPIC_0000001145894431__b937211317480">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a757ac543827e4e4f916b701105eaa75b"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_1">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u10b2a101bc86425dbe47de0ca89c878d"><li id="EN-US_TOPIC_0000001145894431__ld03c6b8c6f2c456c99ce7f03ea3304fb"><strong id="EN-US_TOPIC_0000001145894431__b842352706171310">on</strong> indicates that execution plans are generated on CNs and DNs separately.</li><li id="EN-US_TOPIC_0000001145894431__l4754a99b0b5c4d0cbd9f8269fa585358"><strong id="EN-US_TOPIC_0000001145894431__b944056124171319">off</strong> indicates that the distributed framework is used. Execution plans are generated on CNs and then sent to DNs for execution.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a5949a8effdbd4cbe9d7cdd3dbe25245b"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_aa151e2b3bcc44a9fbb6d168392bfb2a8">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706143455">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section38449529239"><h4 class="sectiontitle">enable_trigger_shipping</h4><p id="EN-US_TOPIC_0000001145894431__p1684445212236"><strong id="EN-US_TOPIC_0000001145894431__b9556145816383">Parameter description</strong>: Specifies whether the trigger can be pushed to DNs for execution.</p>
<p id="EN-US_TOPIC_0000001145894431__p822820541374"><strong id="EN-US_TOPIC_0000001145894431__b215711159489">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p88451652172317"><strong id="EN-US_TOPIC_0000001145894431__b1734414807">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul11845125212232"><li id="EN-US_TOPIC_0000001145894431__li58451252172319"><strong id="EN-US_TOPIC_0000001145894431__b2769212153911">on</strong> indicates that the trigger can be pushed to DNs for execution.</li><li id="EN-US_TOPIC_0000001145894431__li7845105219233"><strong id="EN-US_TOPIC_0000001145894431__b46855479396">off</strong> indicates that the trigger cannot be pushed to DNs. It must be executed on the CN.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p208453520235"><strong id="EN-US_TOPIC_0000001145894431__b1838312346">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b609578962">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s8bc5a77e871d44c58a8794aa67e22bda"><h4 class="sectiontitle">enable_remotejoin</h4><p id="EN-US_TOPIC_0000001145894431__ab6d6c76b6ee6465c82d16f405f1af815"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_a69d70227e2d945a1b5c9a7f42d244fb6">Parameter description:</strong> Specifies whether JOIN operation plans can be delivered to DNs for execution.</p>
<p id="EN-US_TOPIC_0000001145894431__p1994615119382"><strong id="EN-US_TOPIC_0000001145894431__b9744121519483">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a3ebd295205e542cca3529fa2009c23d2"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_3">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u868c5d7f3bb0475199da69d0fd617fe3"><li id="EN-US_TOPIC_0000001145894431__l08acbf11397a4616a8dce71066a31b58"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270617174_1">on</strong> indicates that JOIN operation plans can be delivered to DNs for execution.</li><li id="EN-US_TOPIC_0000001145894431__l8ae82932916b49c287a321626b18ed41"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b1349329973171712_1">off</strong> indicates that JOIN operation plans cannot be delivered to DNs for execution.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a371dc7f4a8bb414b9dc61a0007f6927a"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_ae6880ce5466c4e13bdd758212edfcfa1">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706143542">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__sb2240017245f4f19bc88b277086efca5"><h4 class="sectiontitle">enable_remotegroup</h4><p id="EN-US_TOPIC_0000001145894431__ae15190f7d24145d383647184ea04dc7f"><strong id="EN-US_TOPIC_0000001145894431__b1169914253414">Parameter description:</strong> Specifies whether the execution plans of <strong id="EN-US_TOPIC_0000001145894431__b1870017258413">GROUP BY</strong> and <strong id="EN-US_TOPIC_0000001145894431__b170152510414">AGGREGATE</strong> can be delivered to DNs for execution.</p>
<p id="EN-US_TOPIC_0000001145894431__p9469112382"><strong id="EN-US_TOPIC_0000001145894431__b19145101654813">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a1de1f6d82a914d988acd4d735e656b8c"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_5">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u3776878a482e48faa55cafbdf0a113de"><li id="EN-US_TOPIC_0000001145894431__lfea5ba4096f84759a0c4b0ba6a4f4ac4"><strong id="EN-US_TOPIC_0000001145894431__b157517084214">on</strong> indicates that the execution plans of <strong id="EN-US_TOPIC_0000001145894431__b1756015423">GROUP BY</strong> and <strong id="EN-US_TOPIC_0000001145894431__b157615018429">AGGREGATE</strong> can be delivered to DNs for execution.</li><li id="EN-US_TOPIC_0000001145894431__l84eaea0b3e524552b089104f7b49a700"><strong id="EN-US_TOPIC_0000001145894431__b164851014164110">off</strong> indicates that the execution plans of <strong id="EN-US_TOPIC_0000001145894431__b12485131417412">GROUP BY</strong> and <strong id="EN-US_TOPIC_0000001145894431__b94862146410">AGGREGATE</strong> cannot be delivered to DNs for execution.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__aa10eb6b9c8e34382898a85f464fcf103"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_a724a1d7e94ce4608b5f61929de038644">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706143724">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s11c7f4a137e7460fbcbd2a4d2fcd9204"><h4 class="sectiontitle">enable_remotelimit</h4><p id="EN-US_TOPIC_0000001145894431__ab3440e31dab44ff4bacfe03bef1cf0c4"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b179411486172024">Parameter description</strong>: Specifies whether the execution plan specified in the LIMIT clause can be pushed down to DNs for execution.</p>
<p id="EN-US_TOPIC_0000001145894431__p16604102073811"><strong id="EN-US_TOPIC_0000001145894431__b042581616484">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__acf840ad284b24d3c9ad65055b7ea857e"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_7">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ub0b637f122654199b6703d8217ee9212"><li id="EN-US_TOPIC_0000001145894431__l41b180c143e8480480ead58176df9c5a"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270617174_5">on</strong> indicates that the execution plan specified in the LIMIT clause can be pushed down to DNs for execution.</li><li id="EN-US_TOPIC_0000001145894431__la84c159608864ba39c88f819ea43ed03"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b1349329973171712_5">off</strong> indicates that the execution plan specified in the LIMIT clause cannot be delivered to DNs for execution.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__aeaba26fb6e464dc4958691b4faf2381d"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_abad37691a20b432582ae726a5566ec02">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706143839">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__sad98e37675e1431e8f386cfd7b43c0c0"><h4 class="sectiontitle">enable_remotesort</h4><p id="EN-US_TOPIC_0000001145894431__aa62ac95fa0244da49b9f9f1030845882"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_ac8f894e1d6f94603b957daeb694887ce">Parameter description:</strong> Specifies whether the execution plan of the ORDER BY clause can be delivered to DNs for execution.</p>
<p id="EN-US_TOPIC_0000001145894431__p67529113811"><strong id="EN-US_TOPIC_0000001145894431__b666351610480">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a205bc519657b459b8002a71ba2668828"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_9">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u8198ccf46a5b4c03b4d4057f780b5332"><li id="EN-US_TOPIC_0000001145894431__ld89eda7937eb41d181bea4d0d22053a8"><strong id="EN-US_TOPIC_0000001145894431__b84235270617174">on</strong> indicates that the execution plan of the ORDER BY clause can be delivered to DNs for execution.</li><li id="EN-US_TOPIC_0000001145894431__l328eb35b743d4c0e81332da92d9f5c3f"><strong id="EN-US_TOPIC_0000001145894431__b1349329973171712">off</strong> indicates that the execution plan of the ORDER BY clause cannot be delivered to DNs for execution.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__ad1c67ef19d4a48cc8f9829daa9615839"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_a54aa90819f334704a86ce6893b38d77e">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706143920">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section112190396354"><h4 class="sectiontitle">enable_join_pseudoconst</h4><p id="EN-US_TOPIC_0000001145894431__p82195398354"><strong id="EN-US_TOPIC_0000001145894431__b10240648209">Parameter description</strong>: Specifies whether joining with the pseudo constant is allowed. A pseudo constant indicates that the variables on both sides of a join are identical to the same constant.</p>
<p id="EN-US_TOPIC_0000001145894431__p399519366385"><strong id="EN-US_TOPIC_0000001145894431__b108551316104810">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p15219173913352"><strong id="EN-US_TOPIC_0000001145894431__b14865122200">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul1421903919354"><li id="EN-US_TOPIC_0000001145894431__li521983914353"><strong id="EN-US_TOPIC_0000001145894431__b545171910116">on</strong> indicates that joining with the pseudo constant is allowed.</li><li id="EN-US_TOPIC_0000001145894431__li14219133911355"><strong id="EN-US_TOPIC_0000001145894431__b21041326418">off</strong> indicates that joining with the pseudo constant is not allowed.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p02193391354"><strong id="EN-US_TOPIC_0000001145894431__b208874292112">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b16887192914114">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section74494615103"><h4 class="sectiontitle">cost_model_version</h4><p id="EN-US_TOPIC_0000001145894431__p544184617101"><strong id="EN-US_TOPIC_0000001145894431__b10419125416712">Parameter description</strong>: Specifies the model used for cost estimation in the application scenario. This parameter affects the distinct estimation of the expression, HashJoin cost model, estimation of the number of rows, distribution key selection during redistribution, and estimation of the number of aggregate rows.</p>
<p id="EN-US_TOPIC_0000001145894431__p174484641010"><strong id="EN-US_TOPIC_0000001145894431__b1892375041916">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p54411462108"><strong id="EN-US_TOPIC_0000001145894431__b1584843718252">Value range</strong>: <strong id="EN-US_TOPIC_0000001145894431__b898365014259">0</strong>, <strong id="EN-US_TOPIC_0000001145894431__b8173144572518">1</strong>, or <strong id="EN-US_TOPIC_0000001145894431__b1351119479232">2</strong></p>
<ul id="EN-US_TOPIC_0000001145894431__ul15785113214221"><li id="EN-US_TOPIC_0000001145894431__li37861432122218"><strong id="EN-US_TOPIC_0000001145894431__b152501221172320">0</strong> indicates that the original cost estimation model is used.</li><li id="EN-US_TOPIC_0000001145894431__li2078673282219"><strong id="EN-US_TOPIC_0000001145894431__b17212123122410">1</strong> indicates that the enhanced distinct estimation of the expression, HashJoin cost estimation model, estimation of the number of rows, distribution key selection during redistribution, and estimation of the number of aggregate rows are used on the basis of <strong id="EN-US_TOPIC_0000001145894431__b1594444318283">0</strong>.</li><li id="EN-US_TOPIC_0000001145894431__li1691422145214"><strong id="EN-US_TOPIC_0000001145894431__b752515062818">2</strong> indicates that the ANALYZE sampling algorithm with better randomicity is used on the basis of <strong id="EN-US_TOPIC_0000001145894431__b11194185993116">1</strong> to improve the accuracy of statistics collection.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p444246151011"><strong id="EN-US_TOPIC_0000001145894431__b19115517122312">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b14120201710235">1</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s32fe2a2b19b1450baedd6e65d4bac6ea"><h4 class="sectiontitle">debug_assertions</h4><p id="EN-US_TOPIC_0000001145894431__a05cfea29c6214a519773694009e5707a"><strong id="EN-US_TOPIC_0000001145894431__b50318994434350">Parameter description</strong>: Specifies whether to enable various assertion checks. This parameter assists in debugging. If you are experiencing strange problems or crashes, set this parameter to <strong id="EN-US_TOPIC_0000001145894431__b595816234528">on</strong> to identify programming defects. To use this parameter, the macro USE_ASSERT_CHECKING must be defined (through the configure option <strong id="EN-US_TOPIC_0000001145894431__b14619182605218">--enable-cassert</strong>) during the <span id="EN-US_TOPIC_0000001145894431__text1849355354">GaussDB(DWS)</span> compilation.</p>
<p id="EN-US_TOPIC_0000001145894431__p3525144812382"><strong id="EN-US_TOPIC_0000001145894431__b199081417114816">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a5c21773f39c042cb835b4f663569eb78"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_14">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u6772101d8fcd422fa6c6ce179713b431"><li id="EN-US_TOPIC_0000001145894431__l5cc38d58892f483a9f19e41c2ca0ae13"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b8423527069014_1">on</strong> indicates that various assertion checks are enabled.</li><li id="EN-US_TOPIC_0000001145894431__l00217b2f698a4277b4414e4ba8c4101c"><strong id="EN-US_TOPIC_0000001145894431__b2146935600142324">off</strong> indicates that various assertion checks are disabled.</li></ul>
<div class="note" id="EN-US_TOPIC_0000001145894431__n93f88db54a9d4822a6cf032ff50c1357"><img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><div class="notebody"><p id="EN-US_TOPIC_0000001145894431__abaf15f3c025546189c26b360fa2deaaf">This parameter is set to <strong id="EN-US_TOPIC_0000001145894431__b174881341185213">on</strong> by default if <span id="EN-US_TOPIC_0000001145894431__text1728374027">GaussDB(DWS)</span> is compiled with various assertion checks enabled.</p>
</div></div>
<p id="EN-US_TOPIC_0000001145894431__ad4809c6762fa43b8943cec963c7d184e"><strong id="EN-US_TOPIC_0000001145894431__b1223814775212">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b172386479524">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__sdca10fd86da9479bb6abb9dc88351c4e"><h4 class="sectiontitle">distribute_test_param</h4><p id="EN-US_TOPIC_0000001145894431__a78fb2f6bdaa24c15b964b10dcda864a4"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b8423527069226">Parameter description</strong>: Specifies whether the embedded test stubs for testing the distribution framework take effect. In most cases, developers embed some test stubs in the code during fault injection tests. Each test stub is identified by a unique name. The value of this parameter is a triplet that includes three values: thread level, test stub name, and error level of the injected fault. The three values are separated by commas (,).</p>
<p id="EN-US_TOPIC_0000001145894431__p62517586381"><strong id="EN-US_TOPIC_0000001145894431__b723722119481">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a313f0b0ef5cc4845a77cbad60979c280"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b12382370659551">Value range</strong>: a string indicating the name of any embedded test stub.</p>
<p id="EN-US_TOPIC_0000001145894431__aadf6eba9f06b444f8ee9d8d80abd09cc"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10614468999657">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706144832">-1, default, default</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section118984511015"><h4 class="sectiontitle">ignore_checksum_failure</h4><p id="EN-US_TOPIC_0000001145894431__p4931245107"><strong id="EN-US_TOPIC_0000001145894431__b12518437412">Parameter description</strong>: Sets whether to ignore check failures (but still generates an alarm) and continues reading data. This parameter is valid only when enable_crc_check is set to <strong id="EN-US_TOPIC_0000001145894431__b1755303882311">on</strong>. Continuing reading data may result in breakdown, damaged data being transferred or hidden, failure of data recovery from remote nodes, or other serious problems. You are not advised to modify the settings.</p>
<p id="EN-US_TOPIC_0000001145894431__p13519161181519"><strong id="EN-US_TOPIC_0000001145894431__b09912210481">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__p210512451804"><strong id="EN-US_TOPIC_0000001145894431__b1928909451">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul51717251676"><li id="EN-US_TOPIC_0000001145894431__li18201253715"><strong id="EN-US_TOPIC_0000001145894431__b6208253064">on</strong> indicates that data check errors are ignored.</li><li id="EN-US_TOPIC_0000001145894431__li026202512717"><strong id="EN-US_TOPIC_0000001145894431__b156401023777">off</strong> indicates that data check errors are reported.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p1611017458017"><strong id="EN-US_TOPIC_0000001145894431__b367826483">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b1144840684">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__safc6199e99a24768a3e51a4a1188196b"><h4 class="sectiontitle">enable_colstore</h4><p id="EN-US_TOPIC_0000001145894431__ac11e112ae8384272a6a850092ec6e727"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b160434229691035">Parameter description</strong>: Specifies whether to create a table as a column-store table by default when no storage method is specified. The value for each node must be the same. This parameter is used for tests. Users are not allowed to enable it.</p>
<p id="EN-US_TOPIC_0000001145894431__p5993152731517"><strong id="EN-US_TOPIC_0000001145894431__b397242334813">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__ab00ab4294e4d421686c015d02bfc8ea2"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_18">Value range</strong>: Boolean</p>
<p id="EN-US_TOPIC_0000001145894431__ab7daa137c4354b7caa72b473ff22836a"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_8">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706145026">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section16321134218121"><h4 class="sectiontitle">enable_force_vector_engine</h4><p id="EN-US_TOPIC_0000001145894431__p143221142141211"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0085031973_en-us_topic_0059778871_en-us_topic_0058967732_b131980753891943">Parameter description</strong>: Specifies whether to forcibly generate vectorized execution plans for a vectorized execution operator if the operator's child node is a non-vectorized operator. When this parameter is set to <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0085031973_b113821986314271">on</strong>, vectorized execution plans are forcibly generated. When <strong id="EN-US_TOPIC_0000001145894431__b43785211859">enable_force_vector_engine</strong> is enabled, no matter it is a row-store table, column-store table, or hybrid row-column store table, if the plantree does not contain scenarios that do not support vectorization, the vectorized executor is forcibly used.</p>
<p id="EN-US_TOPIC_0000001145894431__p10322194210123"><strong id="EN-US_TOPIC_0000001145894431__b99985101256">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p173221542121218"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_20">Value range</strong>: Boolean</p>
<p id="EN-US_TOPIC_0000001145894431__p1032374217126"><strong id="EN-US_TOPIC_0000001145894431__b1629419127518">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b1729412121350">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__saacf655a727c4c63bd3e1ee776dd00e6"><h4 class="sectiontitle">enable_csqual_pushdown</h4><p id="EN-US_TOPIC_0000001145894431__a93079ac4190c44db91acaf70333a3cc6"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b147714143392856">Parameter description</strong>: Specifies whether to deliver filter criteria for a rough check during query.</p>
<p id="EN-US_TOPIC_0000001145894431__p1421711434157"><strong id="EN-US_TOPIC_0000001145894431__b56321624154819">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__a655332328fbd45a68fbb7c06ea4ca072"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_22">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__uac0f987951354354a341c15781ab8592"><li id="EN-US_TOPIC_0000001145894431__l1d1ca3de91d5434a9df370a8b8be4b7a"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706152429">on</strong> indicates that a rough check is performed with filter criteria delivered during query.</li><li id="EN-US_TOPIC_0000001145894431__lf70d8ef42ace432b83236ca9aaf6a02f"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b131058467152452">off</strong> indicates that a rough check is performed without filter criteria delivered during query.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a1a980e682a264e6798c7b45e3ee107a4"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b37941181103245_4">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270614521">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s3c82e3805aef453eab87dee4ab61190d"><h4 class="sectiontitle">explain_dna_file</h4><p id="EN-US_TOPIC_0000001145894431__a920efc122e2f4d2b8fe2ab08d6945c3b"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0085031973_en-us_topic_0059778871_en-us_topic_0058967732_b36485115993157">Parameter description</strong>: Specifies the name of a CSV file exported when <a href="#EN-US_TOPIC_0000001145894431__s16fe71bb07ef45c4b3119ee670eac7d1">explain_perf_mode</a> is set to <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__en-us_topic_0085031973_en-us_topic_0059778871_en-us_topic_0058967732_parmvalue55512574493247"><b>run</b></span>.</p>
<p id="EN-US_TOPIC_0000001145894431__p104601227193913"><strong id="EN-US_TOPIC_0000001145894431__b28321824124810">Type</strong>: USERSET</p>
<div class="notice" id="EN-US_TOPIC_0000001145894431__n6e35156d88de447fbdac1a0bd8ab4771"><span class="noticetitle"><img src="public_sys-resources/notice_3.0-en-us.png"> </span><div class="noticebody"><p id="EN-US_TOPIC_0000001145894431__af356829a5ec947be8d02a791ac094ea7">The value of this parameter must be an absolute path plus a file name with the extension <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b8423527069364">.csv</strong>.</p>
</div></div>
<p id="EN-US_TOPIC_0000001145894431__a6ce6fa006e2841dc9cb0bc7d5dd4be4b"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_a7f98c2d88a4543de9a6e560e8c359cf0">Value range</strong>: a string</p>
<p id="EN-US_TOPIC_0000001145894431__a60216fdefbfe4d10bf305ebb7b863813"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_afd123f4efdd44e96bd67b242ad5975da">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706145423">NULL</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s16fe71bb07ef45c4b3119ee670eac7d1"><a name="EN-US_TOPIC_0000001145894431__s16fe71bb07ef45c4b3119ee670eac7d1"></a><a name="s16fe71bb07ef45c4b3119ee670eac7d1"></a><h4 class="sectiontitle">explain_perf_mode</h4><p id="EN-US_TOPIC_0000001145894431__ada204358a8cb43658b2f5ae8b9a60139"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b149185851893626">Parameter description</strong>: Specifies the display format of the <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706142449">explain</strong> command.</p>
<p id="EN-US_TOPIC_0000001145894431__p4732143718393"><strong id="EN-US_TOPIC_0000001145894431__b10995524114812">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__aa9ee0691f9ed453cb9931d0aabdd34eb"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b214534291393731">Value range</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706145456">normal</strong>, <strong id="EN-US_TOPIC_0000001145894431__b842352706145459">pretty</strong>, <strong id="EN-US_TOPIC_0000001145894431__b84235270614552">summary</strong>, and <strong id="EN-US_TOPIC_0000001145894431__b84235270614559">run</strong></p>
<ul id="EN-US_TOPIC_0000001145894431__u093b8fae322b4b11bcd2e4913fb303ab"><li id="EN-US_TOPIC_0000001145894431__l069780ebfeff4d30adcf489cb9a9ed50"><strong id="EN-US_TOPIC_0000001145894431__b3125164205312">normal</strong> indicates that the default printing format is used.</li><li id="EN-US_TOPIC_0000001145894431__l5bbc2899ea334ba6bd4219e61ff3a261"><strong id="EN-US_TOPIC_0000001145894431__b13579185105317">pretty</strong> indicates that the optimized display mode of <span id="EN-US_TOPIC_0000001145894431__text100928589">GaussDB(DWS)</span> is used. A new format contains a plan node ID, directly and effectively analyzing performance.</li><li id="EN-US_TOPIC_0000001145894431__lb7676c1e2daf456f96463360b93340bc"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270693923">summary</strong> indicates that the analysis result based on such information is printed in addition to the printed information in the format specified by <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_b404011371162013">pretty</strong>.</li><li id="EN-US_TOPIC_0000001145894431__le4bdfae778f1488faf3d91a8979ecf12"><strong id="EN-US_TOPIC_0000001145894431__b79458795514326">run</strong> indicates that in addition to the printed information specified by <strong id="EN-US_TOPIC_0000001145894431__b195065478014326">summary</strong>, the database exports the information as a CSV file.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a3dbeabec56f34925be87f775ec668c63"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_ae87a28cece5946d8a210b66574ef37e4">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_b842352706151651">pretty</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section11450659472"><h4 class="sectiontitle">join_num_distinct</h4><p id="EN-US_TOPIC_0000001145894431__p114501559373"><strong id="EN-US_TOPIC_0000001145894431__b209528182714">Parameter description</strong>: Controls the default distinct value of the join column or expression in application scenarios.</p>
<p id="EN-US_TOPIC_0000001145894431__p1845011596717"><strong id="EN-US_TOPIC_0000001145894431__b201138599275">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p3450195911710"><strong id="EN-US_TOPIC_0000001145894431__b2561512162818">Value range</strong>: a double-precision floating point number greater than or equal to <strong id="EN-US_TOPIC_0000001145894431__b16359142411287">-100</strong>. Decimals may be truncated when displayed on clients.</p>
<ul id="EN-US_TOPIC_0000001145894431__ul31359317351"><li id="EN-US_TOPIC_0000001145894431__li14135831113518">If the value is greater than <strong id="EN-US_TOPIC_0000001145894431__b52078171298">0</strong>, the value is used as the default distinct value.</li><li id="EN-US_TOPIC_0000001145894431__li41361831143515">If the value is greater than or equal to <strong id="EN-US_TOPIC_0000001145894431__b1862173014293">-100</strong> and less than <strong id="EN-US_TOPIC_0000001145894431__b5831163517292">0</strong>, it means the percentage used to estimate the default distinct value.</li><li id="EN-US_TOPIC_0000001145894431__li1713613312355">If the value is <strong id="EN-US_TOPIC_0000001145894431__b48961198304">0</strong>, the default distinct value is <strong id="EN-US_TOPIC_0000001145894431__b0504125373011">200</strong>.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p411396133015"><strong id="EN-US_TOPIC_0000001145894431__b19441124916719">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b44441491971">-20</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section1978024313357"><h4 class="sectiontitle">qual_num_distinct</h4><p id="EN-US_TOPIC_0000001145894431__p5780104303520"><strong id="EN-US_TOPIC_0000001145894431__b79031555143016">Parameter description</strong>: Controls the default distinct value of the filter column or expression in application scenarios.</p>
<p id="EN-US_TOPIC_0000001145894431__p77801243173512"><strong id="EN-US_TOPIC_0000001145894431__b48221805332">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p57801743143511"><strong id="EN-US_TOPIC_0000001145894431__b17880251336">Value range</strong>: a double-precision floating point number greater than or equal to <strong id="EN-US_TOPIC_0000001145894431__b388516514331">-100</strong>. Decimals may be truncated when displayed on clients.</p>
<ul id="EN-US_TOPIC_0000001145894431__ul11102053123813"><li id="EN-US_TOPIC_0000001145894431__li2011015316386">If the value is greater than <strong id="EN-US_TOPIC_0000001145894431__b97899723312">0</strong>, the value is used as the default distinct value.</li><li id="EN-US_TOPIC_0000001145894431__li13110155343820">If the value is greater than or equal to <strong id="EN-US_TOPIC_0000001145894431__b191913913311">-100</strong> and less than <strong id="EN-US_TOPIC_0000001145894431__b1919892332">0</strong>, it means the percentage used to estimate the default distinct value.</li><li id="EN-US_TOPIC_0000001145894431__li71105531381">If the value is <strong id="EN-US_TOPIC_0000001145894431__b161991510143310">0</strong>, the default distinct value is <strong id="EN-US_TOPIC_0000001145894431__b8200710163319">200</strong>.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p1178154363518"><strong id="EN-US_TOPIC_0000001145894431__b13687101183314">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b1668710117338">200</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__seea5c278b3cb4517b9030ac57cf721fa"><h4 class="sectiontitle">trace_notify</h4><p id="EN-US_TOPIC_0000001145894431__ad0058565f0774d41a562157eebdb16d2"><strong id="EN-US_TOPIC_0000001145894431__b21451213145310">Parameter description</strong>: Specifies whether to generate a large amount of debugging output for the <strong id="EN-US_TOPIC_0000001145894431__b18150161335311">LISTEN</strong> and <strong id="EN-US_TOPIC_0000001145894431__b915010137538">NOTIFY</strong> commands. <a href="dws_04_0915.html#EN-US_TOPIC_0000001098655026__sbd8ad9bb6b9b48ba97f998f060dc56f3">client_min_messages</a> or <a href="dws_04_0915.html#EN-US_TOPIC_0000001098655026__s1ffb0797361d413d875381200fed970b">log_min_messages</a> must be <strong id="EN-US_TOPIC_0000001145894431__b1265515175318">DEBUG1</strong> or lower so that such output can be recorded in the logs on the client or server separately.</p>
<p id="EN-US_TOPIC_0000001145894431__p11701165293915"><strong id="EN-US_TOPIC_0000001145894431__b189125266488">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a3d3a8f42558a480291e75bc24995ef71"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_26">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__udbe6bc9bde1642aa9df7a003b7030abd"><li id="EN-US_TOPIC_0000001145894431__la5e43b7f057e4736958efc5fb94fa52e"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270610156_1">on</strong> indicates that the function is enabled.</li><li id="EN-US_TOPIC_0000001145894431__lc779b16b9ba74116aa7ba4fa4a174094"><strong id="EN-US_TOPIC_0000001145894431__b58111847934350">off</strong> indicates that the function is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a99607910666b4b8fbbaa9b003f6f6fce"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_14">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b8423527061523">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s20b0fc5448114af5a79ff4a473123018"><h4 class="sectiontitle">trace_recovery_messages</h4><p id="EN-US_TOPIC_0000001145894431__a22d9a47a1c794d9b84bc9aeb63b6df2a"><strong id="EN-US_TOPIC_0000001145894431__b113173244531">Parameter description</strong>: Specifies whether to enable logging of recovery-related debugging output. This parameter allows users to overwrite the normal setting of <a href="dws_04_0915.html#EN-US_TOPIC_0000001098655026__s1ffb0797361d413d875381200fed970b">log_min_messages</a>, but only for specific messages. This is intended for use in debugging the standby server.</p>
<p id="EN-US_TOPIC_0000001145894431__p1873281142213"><strong id="EN-US_TOPIC_0000001145894431__b1136633019488">Type</strong>: SIGHUP</p>
<p id="EN-US_TOPIC_0000001145894431__a8bf905b7eb87439ca7a6a0f10c26f143"><strong id="EN-US_TOPIC_0000001145894431__b295573135320">Value range</strong>: enumerated values. Valid values include <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue159561731145320"><b>debug5</b></span>, <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue1295612313532"><b>debug4</b></span>, <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue095716317535"><b>debug3</b></span>, <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue1295733185312"><b>debug2</b></span>, <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue1895743175314"><b>debug1</b></span>, and <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue16958103110535"><b>log</b></span>. For details about the parameter values, see <a href="dws_04_0915.html#EN-US_TOPIC_0000001098655026__s1ffb0797361d413d875381200fed970b">log_min_messages</a>.</p>
<p id="EN-US_TOPIC_0000001145894431__a6ea186974b914e7f90f04bc6208a1c29"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0085031973_b1826453812813">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0085031973_b12654381815">log</strong></p>
<div class="note" id="EN-US_TOPIC_0000001145894431__note1052125122911"><img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><div class="notebody"><ul id="EN-US_TOPIC_0000001145894431__ul119722813290"><li id="EN-US_TOPIC_0000001145894431__li19724892913"><strong id="EN-US_TOPIC_0000001145894431__b8423527061548">log</strong> indicates that recovery-related debugging information will not be logged.</li><li id="EN-US_TOPIC_0000001145894431__li99728814291">Except the default value <strong id="EN-US_TOPIC_0000001145894431__b13940216161111">log</strong>, each of the other values indicates that recovery-related debugging information at the specified level will also be logged. Common settings of <strong id="EN-US_TOPIC_0000001145894431__b171717142613">log_min_messages</strong> will unconditionally record information into server logs.</li></ul>
</div></div>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s2d5c332082224e378f4ab7e2447dde6c"><h4 class="sectiontitle">trace_sort</h4><p id="EN-US_TOPIC_0000001145894431__a72413efd08da4a5bbb224838a824966a"><strong id="EN-US_TOPIC_0000001145894431__b165535402535">Parameter description</strong>: Specifies whether to display information about resource usage during sorting operations in logs. This parameter is available only when the macro TRACE_SORT is defined during the <span id="EN-US_TOPIC_0000001145894431__text1711948848">GaussDB(DWS)</span> compilation. However, TRACE_SORT is currently defined by default.</p>
<p id="EN-US_TOPIC_0000001145894431__p1361116320409"><strong id="EN-US_TOPIC_0000001145894431__b8554930104819">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a595092a7dfe8471fad32cb17cbdd9c81"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_28">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ue76d46acff23480981e797ae8e17a44d"><li id="EN-US_TOPIC_0000001145894431__l40c7c1bca6054f1ea307966adc9428cf"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270610156_3">on</strong> indicates that the function is enabled.</li><li id="EN-US_TOPIC_0000001145894431__l1aeea7e0200d418882c9bd8505331d17"><strong id="EN-US_TOPIC_0000001145894431__b43140288934350">off</strong> indicates that the function is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a2e0d4bd4f56e4d1e96559eeac3d1e88d"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_16">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270615541">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__sfe7e2e59c9a545ecbc8e6aae628255ac"><h4 class="sectiontitle">zero_damaged_pages</h4><p id="EN-US_TOPIC_0000001145894431__a903015a56c2a45bb9819b02413963fbe"><strong id="EN-US_TOPIC_0000001145894431__b8785175014539">Parameter description</strong>: Specifies whether to detect a damaged page header that causes <span id="EN-US_TOPIC_0000001145894431__text1422231576">GaussDB(DWS)</span> to report an error, aborting the current transaction.</p>
<p id="EN-US_TOPIC_0000001145894431__p13276421169"><strong id="EN-US_TOPIC_0000001145894431__b157425301482">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__a06a886b184d242928e16a3811ee3b0dc"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_42">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul171616272293"><li id="EN-US_TOPIC_0000001145894431__li14716327112917"><strong id="EN-US_TOPIC_0000001145894431__b1225038017">on</strong> indicates that the function is enabled.</li><li id="EN-US_TOPIC_0000001145894431__li6716162718295"><strong id="EN-US_TOPIC_0000001145894431__b33161310173315">off</strong> indicates that the function is disabled.</li></ul>
<div class="note" id="EN-US_TOPIC_0000001145894431__note187675162306"><img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><div class="notebody"><ul id="EN-US_TOPIC_0000001145894431__ul793511437383"><li id="EN-US_TOPIC_0000001145894431__li1593564312386">Setting this parameter to <strong id="EN-US_TOPIC_0000001145894431__b162192215337">on</strong> causes the system to report a warning, pad the damaged page with zeros, and then continue with subsequent processing. This behavior will damage data, that is, all rows on the damaged page. However, it allows you to bypass the error and retrieve rows from any undamaged pages that are present in the table. Therefore, it is useful for restoring data that is damaged due to a hardware or software error. In most cases, you are not advised to set this parameter to <strong id="EN-US_TOPIC_0000001145894431__b862974819334">on</strong> unless you do not want to restore data from the damaged pages of a table.</li><li id="EN-US_TOPIC_0000001145894431__li993519439381">For a column-store table, the system will skip the entire CU and then continue processing. The supported scenarios include the CRC check failure, magic check failure, and incorrect CU length.</li></ul>
</div></div>
<p id="EN-US_TOPIC_0000001145894431__a31bb8eb1deec43409023f1a70f523306"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_18">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b8423527061589">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s8ffa7df03f6b4d55aa1b3e536368913d"><h4 class="sectiontitle">string_hash_compatible</h4><p id="EN-US_TOPIC_0000001145894431__aa6526fd3240f49718e4f3d81b48632b0"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706103141">Parameter description</strong>: Specifies whether to use the same method to calculate char-type hash values and varchar- or text-type hash values. Based on the setting of this parameter, you can determine whether a redistribution is required when a distribution column is converted from a char-type data distribution into a varchar- or text-type data distribution.</p>
<p id="EN-US_TOPIC_0000001145894431__p533132622213"><strong id="EN-US_TOPIC_0000001145894431__b3907173044811">Type</strong>: POSTMASTER</p>
<p id="EN-US_TOPIC_0000001145894431__a8ef5e59ac8db48839a8270579ba6ec1a"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_44">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u36d283cd8bc44af7ada13c60d945463d"><li id="EN-US_TOPIC_0000001145894431__lf04dde942bc8421a8cf59300fa9ff9eb"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706103811_1">on</strong> indicates that the same calculation method is used and a redistribution is not required.</li><li id="EN-US_TOPIC_0000001145894431__l58c9064fdae3496bad50383758c610f8"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706103811_3">off</strong> indicates that different calculation methods are used and a redistribution is required.</li></ul>
<div class="note" id="EN-US_TOPIC_0000001145894431__n9afdefc2a9334fbe992c4f9e9d625acd"><img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><div class="notebody"><p id="EN-US_TOPIC_0000001145894431__a96c507c87453495499ce189c2b9cf724">Calculation methods differ in the length of input strings used for calculating hash values. (For a char-type hash value, spaces following a string are not counted as the length. For a text- or varchar-type hash value, the spaces are counted.) The hash value affects the calculation result of queries. To avoid query errors, do not modify this parameter during database running once it is set.</p>
</div></div>
<p id="EN-US_TOPIC_0000001145894431__a5b7229d48ce84f41aa7388045ca6ae03"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_20">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270615156">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s9d3070772fd24cd9934d1eeca2d256c6"><h4 class="sectiontitle">replication_test</h4><p id="EN-US_TOPIC_0000001145894431__adf84caf229ad4a23b409f0bc26db68a2"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706104549">Parameter description</strong>: Specifies whether to enable internal testing on the data replication function.</p>
<p id="EN-US_TOPIC_0000001145894431__p14302015154013"><strong id="EN-US_TOPIC_0000001145894431__b8971731134810">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a1f3fb3921436422b8e4dfb5aac68f1c7"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_46">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ue00e3ea19ad04007a7e4ffac846bc961"><li id="EN-US_TOPIC_0000001145894431__l2c7a7d601cc841a3adc38d04ecac2be9"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706104648">on</strong> indicates that internal testing on the data replication function is enabled.</li><li id="EN-US_TOPIC_0000001145894431__lcecb176464604bf3b2c2e1c4ce61c5f6"><strong id="EN-US_TOPIC_0000001145894431__b46635984134350">off</strong> indicates that internal testing on the data replication function is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__ae8f36833116146f68fddda2d230cb0d8"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_22">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706151612">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s4aa885c181c4403d9942e6951aa67a17"><h4 class="sectiontitle">cost_param</h4><p id="EN-US_TOPIC_0000001145894431__ac27c311ccb834b2f966df3ebc722fffd"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b21094962111229">Parameter description</strong>: Controls use of different estimation methods in specific customer scenarios, allowing estimated values approximating to onsite values. This parameter can control various methods simultaneously by performing AND (&amp;) operations on the bit for each method. A method is selected if its value is not <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__parmvalue2077304747144331"><b>0</b></span>.</p>
<p id="EN-US_TOPIC_0000001145894431__a6fc66e66f8eb46a9844fa2f99e2fc6e8">If <strong id="EN-US_TOPIC_0000001145894431__b101600712244">cost_param &amp; 1</strong> is not set to <strong id="EN-US_TOPIC_0000001145894431__b116114720246">0</strong>, an improvement mechanism is selected for calculating a non-equi join selection rate, which is more accurate in estimation of self-join (join between two same tables). In <span id="EN-US_TOPIC_0000001145894431__ph716116732418">V300R002C00</span> and later, <strong id="EN-US_TOPIC_0000001145894431__b181617772417">cost_param &amp; 1=0</strong> is not used. That is, an optimized formula is selected for calculation.</p>
<p id="EN-US_TOPIC_0000001145894431__a7d3d193f73da479abe8fad983eb097fa">When <span class="parmname" id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_parmname936426231111154"><b>cost_param &amp; 2</b></span> is set to a value other than <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_parmvalue1835860841111154"><b>0</b></span>, the selection rate is estimated based on multiple filter criteria. The lowest selection rate among all filter criteria, but not the product of the selection rates for two tables under a specific filter criterion, is used as the total selection rate. This method is more accurate when a close correlation exists between the columns to be filtered.</p>
<p id="EN-US_TOPIC_0000001145894431__ad34263dc0c2b4bd8a2bcf217cd0c9120">When <span class="parmname" id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_parmname1158438200155445"><b>cost_param &amp; 4</b></span> is not <span class="parmvalue" id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_parmvalue35083637155445"><b>0</b></span>, the selected debugging model is not recommended when the stream node is evaluated.</p>
<p id="EN-US_TOPIC_0000001145894431__p121521152191317">When <strong id="EN-US_TOPIC_0000001145894431__b13103191310334">cost_param &amp; 16</strong> is not <strong id="EN-US_TOPIC_0000001145894431__b61031139337">0</strong>, the model between fully correlated and fully uncorrelated models is used to calculate the comprehensive selection rate of two or more filtering conditions or join conditions. If there are many filtering conditions, the strongly-correlated model is preferred.</p>
<p id="EN-US_TOPIC_0000001145894431__p1269972410403"><strong id="EN-US_TOPIC_0000001145894431__b0273133174812">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__ab3f933e58fae41a684549d0a2d025f5e"><strong id="EN-US_TOPIC_0000001145894431__b72064000734350">Value range</strong>: an integer ranging from 1 to INT_MAX</p>
<p id="EN-US_TOPIC_0000001145894431__ad310eaf261de418c8bc1ccf1e3590774"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b61650132_6">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706151931">16</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s52ddbced6d054fa8aef56b60f4d83850"><h4 class="sectiontitle">convert_string_to_digit</h4><p id="EN-US_TOPIC_0000001145894431__add8460437caa4e1b860dd295b6a76549"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b8423527069283">Parameter description</strong>: Specifies the implicit conversion priority, which determines whether to preferentially convert strings into numbers.</p>
<p id="EN-US_TOPIC_0000001145894431__p1831021321810">In MySQL-compatible mode, this parameter has no impact.</p>
<p id="EN-US_TOPIC_0000001145894431__p1350893218405"><strong id="EN-US_TOPIC_0000001145894431__b114691631114812">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a0b6aa021700240149ad31ccf53ac8370"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_48">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u544a6347e9284295891557791ff71585"><li id="EN-US_TOPIC_0000001145894431__lba07d29043624f8a90b6aad96f09bbf3"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270611217">on</strong> indicates that strings are preferentially converted into numbers.</li><li id="EN-US_TOPIC_0000001145894431__lab36125a2834442d8f99dcdf4b6fa107"><strong id="EN-US_TOPIC_0000001145894431__b1415687635144819">off</strong> indicates that strings are not preferentially converted into numbers.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__ad94a0abb0cac42e7b2cf0e330106c52c"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b6125520212036_2">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706152029">on</strong></p>
<div class="notice" id="EN-US_TOPIC_0000001145894431__note6967113133211"><span class="noticetitle"><img src="public_sys-resources/notice_3.0-en-us.png"> </span><div class="noticebody"><p id="EN-US_TOPIC_0000001145894431__p14903530173011">Modify this parameter only when absolutely necessary because the modification will change the rule for converting internal data types and may cause unexpected results.</p>
</div></div>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s91876ad6d74646e7a825d6dd447667bc"><h4 class="sectiontitle">nls_timestamp_format</h4><p id="EN-US_TOPIC_0000001145894431__a06f00dc9eb1641d0b4c752146bdb92a0"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706112137">Parameter description</strong>: Specifies the default timestamp format.</p>
<p id="EN-US_TOPIC_0000001145894431__p79051641114011"><strong id="EN-US_TOPIC_0000001145894431__b1866711312481">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__af76c48dd086c4fb089c7fec49464823e"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706112225">Value range</strong>: a string</p>
<p id="EN-US_TOPIC_0000001145894431__ad4a6fec483524244bac6fc7e3ecc4aab"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b1912033555112237">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270615213">DD-Mon-YYYY HH:MI:SS.FF AM</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s6e188648d0ad413e871dde5c185c2821"><h4 class="sectiontitle">enable_partitionwise</h4><p id="EN-US_TOPIC_0000001145894431__a725220629e1f40cf8e4b627c7baff6c0"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706112523">Parameter description</strong>: Specifies whether to select an intelligent algorithm for joining partitioned tables.</p>
<p id="EN-US_TOPIC_0000001145894431__p6912155034013"><strong id="EN-US_TOPIC_0000001145894431__b64053244818">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a576f749f40c8416a8675eced33f96506"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b16754081162213">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u7eb29a6f0a0040f69fdcdf8112f59a75"><li id="EN-US_TOPIC_0000001145894431__l548a63a599144a479b542a2ced0b81d7"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270611276_1">on</strong> indicates that an intelligent algorithm is selected.</li><li id="EN-US_TOPIC_0000001145894431__lb9fa7b3aa3c64a3eb7f39f066da0d234"><strong id="EN-US_TOPIC_0000001145894431__b134815161714501">off</strong> indicates that an intelligent algorithm is not selected.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__aafac74f2668743c2b101c784e55ea422"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_24">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270615255">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section825595755117"><h4 class="sectiontitle">enable_partition_dynamic_pruning</h4><p id="EN-US_TOPIC_0000001145894431__p525535714517"><strong id="EN-US_TOPIC_0000001145894431__b163961109401">Parameter description</strong>: Specifies whether dynamic pruning is enabled during partition table scanning.</p>
<p id="EN-US_TOPIC_0000001145894431__p9256125719513"><strong id="EN-US_TOPIC_0000001145894431__b158917131409">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p19256957145111"><strong id="EN-US_TOPIC_0000001145894431__b28402149409">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul20256125745112"><li id="EN-US_TOPIC_0000001145894431__li132566572517"><strong id="EN-US_TOPIC_0000001145894431__b583118589402">on</strong>: enable</li><li id="EN-US_TOPIC_0000001145894431__li16233214535"><strong id="EN-US_TOPIC_0000001145894431__b1624741314418">off</strong>: disable</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p1625615710515"><strong id="EN-US_TOPIC_0000001145894431__b1780991620413">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b5809216114110">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s52a0656d4aec461aa208616489c3362e"><h4 class="sectiontitle">max_user_defined_exception</h4><p id="EN-US_TOPIC_0000001145894431__a5c4f50ae7d464a34a00ade1763814b9c"><strong id="EN-US_TOPIC_0000001145894431__b14891351193213">Parameter description</strong>: Specifies the maximum number of exceptions. The default value cannot be changed.</p>
<p id="EN-US_TOPIC_0000001145894431__p235751194111"><strong id="EN-US_TOPIC_0000001145894431__b420373218482">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__ad1202fa17a6349d191c902d012435006"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_a7a9cc0fdf8de40779cb11862ef669066">Value range</strong>: an integer</p>
<p id="EN-US_TOPIC_0000001145894431__a5a6a6c0f95eb4fda9c6b672ee87ed975"><strong id="EN-US_TOPIC_0000001145894431__b77447017616429">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b3061407016429">1000</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s33ef66a4cb9843db922428a5e4107da1"><h4 class="sectiontitle">datanode_strong_sync</h4><p id="EN-US_TOPIC_0000001145894431__ab71d3f548d9348baa3709158e6b74fc7"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_b842352706102047">Parameter description</strong>: This parameter no longer takes effect.</p>
<p id="EN-US_TOPIC_0000001145894431__p197854824118"><strong id="EN-US_TOPIC_0000001145894431__b12387163217489">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__aef4aa244b4524b7b981b5e42916ad245"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_a65b7a7d09251449ea6605549c1c34541">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__uf61ed5cfe5d247079b8cafd4c8ff7903"><li id="EN-US_TOPIC_0000001145894431__lea2fb4e2d630424d92ef0590da659b69"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706113332_1">on</strong> indicates that forcible synchronization between stream nodes is enabled.</li><li id="EN-US_TOPIC_0000001145894431__l18e953a1a6ab44f8883ba6e23bc46213"><strong id="EN-US_TOPIC_0000001145894431__b629721023145053">off</strong> indicates that forcible synchronization between stream nodes is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a43e0af6a595b4932a33c11011533dda9"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_26">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706152730">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__seb1be9348e6b4482914bc933a9705cec"><h4 class="sectiontitle">enable_debug_vacuum</h4><p id="EN-US_TOPIC_0000001145894431__ab68f9aa677634c1ca827fc52cb2d8724"><strong id="EN-US_TOPIC_0000001145894431__a13f966415fee496092fe4fb981550a59">Parameter description</strong>: Specifies whether to allow output of some VACUUM-related logs for problem locating. This parameter is used only by developers. Common users are advised not to use it.</p>
<p id="EN-US_TOPIC_0000001145894431__p8322182514195"><strong id="EN-US_TOPIC_0000001145894431__b489223219487">Type</strong>: SIGHUP</p>
<p id="EN-US_TOPIC_0000001145894431__a8a5decebb57b491086d3170b265deb0b"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_50">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u9ab38400f6f042c7bc4d00df4d7ba837"><li id="EN-US_TOPIC_0000001145894431__lf6392a118cd74531b9ae624318b00300"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b842352706102618">on/true</strong> indicates that output of vacuum-related logs is allowed.</li><li id="EN-US_TOPIC_0000001145894431__l70a9135718024d3bbeb5a30015a4b664"><strong id="EN-US_TOPIC_0000001145894431__b2122296763145136">off/false</strong> indicates that output of vacuum-related logs is disallowed.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a0634e080637047f7a56a3f3a4cf72db7"><strong id="EN-US_TOPIC_0000001145894431__b117777560">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b409258146">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s46971fbae49a4605b3348ad268c7320b"><h4 class="sectiontitle">enable_global_stats</h4><p id="EN-US_TOPIC_0000001145894431__acd79fb5be55b490b95e00881010673a9"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270613582">Parameter description</strong>: Specifies the current statistics mode. This parameter is used to compare global statistics generation plans and the statistics generation plans for a single DN. This parameter is used for tests. Users are not allowed to enable it.</p>
<p id="EN-US_TOPIC_0000001145894431__p9556100111710"><strong id="EN-US_TOPIC_0000001145894431__b1997043219485">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__abe4f6a24b4434f3886fcae840ea031cf"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_52">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__u3b451e5a0ad745ca875bd9d7dec98b6c"><li id="EN-US_TOPIC_0000001145894431__l78f288fb5d1148e19d2f25b10c954c25"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270614149">on</strong> or <strong id="EN-US_TOPIC_0000001145894431__b10621205113217">true</strong> indicates the global statistics mode.</li><li id="EN-US_TOPIC_0000001145894431__ld4504674b7cf4c1e9deb28525d0d7c7a"><strong id="EN-US_TOPIC_0000001145894431__b1774956203214">off</strong> or <strong id="EN-US_TOPIC_0000001145894431__b1019911373319">false</strong> indicates the single-DN statistics mode.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a7eca7c6c52744a2fa62907340a5e5de0"><strong id="EN-US_TOPIC_0000001145894431__b267748081">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b946931686">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__sdf986a27d14a4eeca7a85218bb0d70fc"><h4 class="sectiontitle">enable_fast_numeric</h4><p id="EN-US_TOPIC_0000001145894431__a20da9895edff4e28b9274ae3dfc1f2ab"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270614311">Parameter description</strong>: Specifies whether to enable optimization for numeric data calculation. Calculation of numeric data is time-consuming. Numeric data is converted into int64- or int128-type data to improve numeric data calculation performance.</p>
<p id="EN-US_TOPIC_0000001145894431__p630411205416"><strong id="EN-US_TOPIC_0000001145894431__b1610813317485">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__ac99cce35f9e940ffb06b531e5dcf68cb"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b10741640_54">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ud15e56a590934f88ac221ac4fcb815fe"><li id="EN-US_TOPIC_0000001145894431__lc0db949573864e7db7a305c4e77e1c8b"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b84235270614345">on/true</strong> indicates that optimization for numeric data calculation is enabled.</li><li id="EN-US_TOPIC_0000001145894431__l032a62540eb84f518adea91e01548fa6"><strong id="EN-US_TOPIC_0000001145894431__b1227554481145544">off/false</strong> indicates that optimization for numeric data calculation is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a334385cff15647fabe235abf8e4d710f"><strong id="EN-US_TOPIC_0000001145894431__b2046876950">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b2123279729">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section1731164732612"><h4 class="sectiontitle">enable_row_fast_numeric</h4><p id="EN-US_TOPIC_0000001145894431__p1631114712614"><strong id="EN-US_TOPIC_0000001145894431__b3501545134515">Parameter description</strong>: Specifies the format in which numeric data in a row-store table is spilled to disks.</p>
<p id="EN-US_TOPIC_0000001145894431__p53111247192616"><strong id="EN-US_TOPIC_0000001145894431__b1191175114446">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p731112479265"><strong id="EN-US_TOPIC_0000001145894431__b15256145319442">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul19311114713266"><li id="EN-US_TOPIC_0000001145894431__li1431114475263"><strong id="EN-US_TOPIC_0000001145894431__b17743132911498">on/true</strong> indicates that numeric data in a row-store table is spilled to disks in bigint format.</li><li id="EN-US_TOPIC_0000001145894431__li1131184762613"><strong id="EN-US_TOPIC_0000001145894431__b944417154503">off/false</strong> indicates that numeric data in a row-store table is spilled to disks in the original format.</li></ul>
<div class="notice" id="EN-US_TOPIC_0000001145894431__note1086416237362"><span class="noticetitle"><img src="public_sys-resources/notice_3.0-en-us.png"> </span><div class="noticebody"><p id="EN-US_TOPIC_0000001145894431__p1828141410376">If this parameter is set to <strong id="EN-US_TOPIC_0000001145894431__b8335203255815">on</strong>, you are advised to enable <strong id="EN-US_TOPIC_0000001145894431__b1759964695917">enable_force_vector_engine</strong> to improve the query performance of large data sets. However, compared with the original format, there is a high probability that the bigint format occupies more disk space. For example, the TPC-H test set occupies about 7% more space (reference value, may vary depending on the environment).</p>
</div></div>
<p id="EN-US_TOPIC_0000001145894431__p10864102373617"><strong id="EN-US_TOPIC_0000001145894431__b26712713451">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b177415271451">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s333914ac6c8f4cd4a6ce9ed73bb2be14"><h4 class="sectiontitle">rewrite_rule</h4><p id="EN-US_TOPIC_0000001145894431__aadb206b6e06144aba4dc5a86a46b8b54"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_b84235270695334">Parameter description</strong>: Specifies the rewriting rule for enabled optional queries. Some query rewriting rules are optional. Enabling them cannot always improve query efficiency. In a specific customer scenario, you can set the query rewriting rules through the GUC parameter to achieve optimal query efficiency.</p>
<p id="EN-US_TOPIC_0000001145894431__acff5283804694eb0bff3536e253f5257">This parameter can control the combination of query rewriting rules, for example, there are multiple rewriting rules: rule1, rule2, rule3, and rule4. To set the parameters, you can perform the following operations:</p>
<pre class="codeblock" id="EN-US_TOPIC_0000001145894431__c0f33646897a847c78b97cc954edd6337">set rewrite_rule=rule1; --Enable query rewriting rule rule1.
set rewrite_rule=rule2,rule3; --Enable query rewriting rules rule2 and rule3.
set rewrite_rule=none; --Disable all optional query rewriting rules.</pre>
<p id="EN-US_TOPIC_0000001145894431__p1698152934113"><strong id="EN-US_TOPIC_0000001145894431__b8351935194812">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a3d8c820d08c0489ba6c10a47476f8b23"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_b44366800195127">Value range</strong>: a string</p>
<ul id="EN-US_TOPIC_0000001145894431__u582a49208d014b459af16e68a402d6df"><li id="EN-US_TOPIC_0000001145894431__l809bf5bea254485d9ac4dc25947b5c18"><strong id="EN-US_TOPIC_0000001145894431__b842352706153518">none</strong>: Does not use any optional query rewriting rules.</li><li id="EN-US_TOPIC_0000001145894431__l23cd64e035524005929848d0127b3d8e"><strong id="EN-US_TOPIC_0000001145894431__b842352706153610">lazyagg</strong>: Uses the Lazy Agg query rewriting rules for eliminating aggregation operations in subqueries.</li><li id="EN-US_TOPIC_0000001145894431__li17831429124620"><strong id="EN-US_TOPIC_0000001145894431__b842352706182636">magicset</strong>: Uses the Magic Set query rewriting rules (from the main query to subqueries).</li><li id="EN-US_TOPIC_0000001145894431__li15390132510245"><strong id="EN-US_TOPIC_0000001145894431__b341618591175">uniquecheck</strong>: Uses the Unique Check rewriting rules. (The scenario where the target column does not contain the expression sublink of the aggregate function can be improved. The function can be enabled only when the value of the target column is unique after the sublink is aggregated based on the associated column. This function is recommended to be used by optimization engineers.)</li><li id="EN-US_TOPIC_0000001145894431__li13943144817253"><strong id="EN-US_TOPIC_0000001145894431__b190617157294">disablerep</strong>: Uses the function that prohibit pulling up sublinks of the replication table. (Disable sublink pull-up for the replication table.)</li><li id="EN-US_TOPIC_0000001145894431__li7688122815254"><strong id="EN-US_TOPIC_0000001145894431__b102691429175011">projection_pushdown</strong>: Uses the Projection Pushdown rewriting rules.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a97c28ae246e3464aa63de98c910603c4"><strong id="EN-US_TOPIC_0000001145894431__b84235270614205">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270617354">magicset</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__s3fe7f177cf2d42d091881dae6a3c9af7"><h4 class="sectiontitle">enable_compress_spill</h4><p id="EN-US_TOPIC_0000001145894431__aa99d2376a98c4f6bb9845a2f805ae184"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967586_b842352706193513_1">Parameter description</strong>: Specifies whether to enable the compression function of writing data to a disk.</p>
<p id="EN-US_TOPIC_0000001145894431__p194476377415"><strong id="EN-US_TOPIC_0000001145894431__b13527133512487">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__a26e8b3ac5a6f44faa01851a91eb084bd"><strong id="EN-US_TOPIC_0000001145894431__b209791372114586">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_ul16131530193"><li id="EN-US_TOPIC_0000001145894431__l92ff8d0ab3874868b1f9b4437b288f1b"><strong id="EN-US_TOPIC_0000001145894431__b1235548773145816">on/true</strong> indicates that optimization for writing data to a disk is enabled.</li><li id="EN-US_TOPIC_0000001145894431__la5c9c3e7b8c9454ab4f5cc71c6ff8f8a"><strong id="EN-US_TOPIC_0000001145894431__b255718568145822">off/false</strong> indicates that optimization for writing data to a disk is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__a1b077fc8586c414290d396164ed37aed"><strong id="EN-US_TOPIC_0000001145894431__b9992201">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b1928773869">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section41951721291"><h4 class="sectiontitle">analysis_options</h4><p id="EN-US_TOPIC_0000001145894431__p2195428918"><strong id="EN-US_TOPIC_0000001145894431__b842352706153759">Parameter description</strong>: Specifies whether to enable function options in the corresponding options to use the corresponding location functions, including data verification and performance statistics. For details, see the options in the value range.</p>
<p id="EN-US_TOPIC_0000001145894431__p863484684112"><strong id="EN-US_TOPIC_0000001145894431__b2083903584818">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p3195621496"><strong id="EN-US_TOPIC_0000001145894431__b656186108">Value range</strong>: a string</p>
<ul id="EN-US_TOPIC_0000001145894431__ul111951521891"><li id="EN-US_TOPIC_0000001145894431__li61956217916"><strong id="EN-US_TOPIC_0000001145894431__b842352706154644">LLVM_COMPILE</strong> indicates that the codegen compilation time of each thread is displayed on the explain performance page.</li><li id="EN-US_TOPIC_0000001145894431__li91951721794"><strong id="EN-US_TOPIC_0000001145894431__b842352706154821">HASH_CONFLICT</strong> indicates that the log file in the <strong id="EN-US_TOPIC_0000001145894431__b842352706154924">pg_log</strong> directory of the DN process displays the hash table statistics, including the hash table size, hash chain length, and hash conflict information.</li><li id="EN-US_TOPIC_0000001145894431__li71958211919"><strong id="EN-US_TOPIC_0000001145894431__b842352706154954">STREAM_DATA_CHECK</strong> indicates that a CRC check is performed on data before and after network data transmission.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p131951321696"><strong id="EN-US_TOPIC_0000001145894431__b842352706155055">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b84235270615511">off(ALL)</strong>, which indicates that no location function is enabled.</p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section11914205152413"><h4 class="sectiontitle">resource_track_log</h4><p id="EN-US_TOPIC_0000001145894431__p9913551132418"><strong id="EN-US_TOPIC_0000001145894431__b16778194335712">Parameter description</strong>: Specifies the log level of self-diagnosis. Currently, this parameter takes effect only in multi-column statistics.</p>
<p id="EN-US_TOPIC_0000001145894431__p1330625614415"><strong id="EN-US_TOPIC_0000001145894431__b14263610486">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p169144514243"><strong id="EN-US_TOPIC_0000001145894431__b896852572">Value range</strong>: a string</p>
<ul id="EN-US_TOPIC_0000001145894431__ul191425192419"><li id="EN-US_TOPIC_0000001145894431__li69141751142416"><strong id="EN-US_TOPIC_0000001145894431__b20566248112">summary</strong>: Brief diagnosis information is displayed.</li><li id="EN-US_TOPIC_0000001145894431__li24317516439"><strong id="EN-US_TOPIC_0000001145894431__b362619271127">detail</strong>: Detailed diagnosis information is displayed.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p925966104415">Currently, the two parameter values differ only when there is an alarm about multi-column statistics not collected. If the parameter is set to <strong id="EN-US_TOPIC_0000001145894431__b124677321226">summary</strong>, such an alarm will not be displayed. If it is set to <strong id="EN-US_TOPIC_0000001145894431__b1446813327219">detail</strong>, such an alarm will be displayed.</p>
<p id="EN-US_TOPIC_0000001145894431__p159147518249"><strong id="EN-US_TOPIC_0000001145894431__b114989281635">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b05001328134">summary</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section189901634112519"><h4 class="sectiontitle">hll_default_log2m</h4><p id="EN-US_TOPIC_0000001145894431__p152961221141812"><strong id="EN-US_TOPIC_0000001145894431__b14594144910312">Parameter description</strong>: Specifies the number of buckets for HLL data. The number of buckets affects the precision of distinct values calculated by HLL. The more buckets there are, the smaller the deviation is. The deviation range is as follows: [–1.04/2<sup id="EN-US_TOPIC_0000001145894431__sup196621119142218">log2m*1/2</sup>, +1.04/2<sup id="EN-US_TOPIC_0000001145894431__sup393323972211">log2m*1/2</sup>]</p>
<p id="EN-US_TOPIC_0000001145894431__p199931419425"><strong id="EN-US_TOPIC_0000001145894431__b72136363486">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p899133412256"><strong id="EN-US_TOPIC_0000001145894431__b899153442514">Value range</strong>: an integer ranging from 10 to 16</p>
<p id="EN-US_TOPIC_0000001145894431__p199912348251"><strong id="EN-US_TOPIC_0000001145894431__b8651523192616">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b42794364267">11</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section185791437112511"><h4 class="sectiontitle">hll_default_regwidth</h4><p id="EN-US_TOPIC_0000001145894431__p658015377251"><strong id="EN-US_TOPIC_0000001145894431__b34591158172618">Parameter description</strong>: Specifies the number of bits in each bucket for HLL data. A larger value indicates more memory occupied by HLL. <strong id="EN-US_TOPIC_0000001145894431__b165038491142">hll_default_regwidth</strong> and <strong id="EN-US_TOPIC_0000001145894431__b6531754111414">hll_default_log2m</strong> determine the maximum number of distinct values that can be calculated by HLL. For details, see <a href="#EN-US_TOPIC_0000001145894431__table05450516616">Table 1</a>.</p>
<p id="EN-US_TOPIC_0000001145894431__p186012144420"><strong id="EN-US_TOPIC_0000001145894431__b037233612488">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p20580173732518"><strong id="EN-US_TOPIC_0000001145894431__b155801637182513">Value range</strong>: an integer ranging from 1 to 5</p>
<p id="EN-US_TOPIC_0000001145894431__p1258016372256"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059779078_a5e8289e264814e01800c00b0d832c9e4">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706162730">5</strong></p>
<div class="tablenoborder"><a name="EN-US_TOPIC_0000001145894431__table05450516616"></a><a name="table05450516616"></a><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001145894431__table05450516616" frame="border" border="1" rules="all"><caption><b>Table 1 </b>Maximum number of calculated distinct values determined by hll_default_log2m and hll_default_regwidth</caption><thead align="left"><tr id="EN-US_TOPIC_0000001145894431__row8546651063"><th align="left" class="cellrowborder" valign="top" width="16.666666666666664%" id="mcps1.3.42.6.2.7.1.1"><p id="EN-US_TOPIC_0000001145894431__p254617515615">log2m</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="16.666666666666664%" id="mcps1.3.42.6.2.7.1.2"><p id="EN-US_TOPIC_0000001145894431__p19546551964">regwidth = 1</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="16.666666666666664%" id="mcps1.3.42.6.2.7.1.3"><p id="EN-US_TOPIC_0000001145894431__p1554655763">regwidth = 2</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="16.666666666666664%" id="mcps1.3.42.6.2.7.1.4"><p id="EN-US_TOPIC_0000001145894431__p195461551168">regwidth = 3</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="16.666666666666664%" id="mcps1.3.42.6.2.7.1.5"><p id="EN-US_TOPIC_0000001145894431__p19546175262">regwidth = 4</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="16.666666666666664%" id="mcps1.3.42.6.2.7.1.6"><p id="EN-US_TOPIC_0000001145894431__p554635064">regwidth = 5</p>
</th>
</tr>
</thead>
<tbody><tr id="EN-US_TOPIC_0000001145894431__row7546145068"><td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.1 "><p id="EN-US_TOPIC_0000001145894431__p65465511610">10</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.2 "><p id="EN-US_TOPIC_0000001145894431__p165462051966">7.4e+02</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.3 "><p id="EN-US_TOPIC_0000001145894431__p35471751267">3.0e+03</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.4 "><p id="EN-US_TOPIC_0000001145894431__p13547751362">4.7e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.5 "><p id="EN-US_TOPIC_0000001145894431__p254716513614">1.2e+07</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.6 "><p id="EN-US_TOPIC_0000001145894431__p2547051965">7.9e+11</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001145894431__row2054725162"><td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.1 "><p id="EN-US_TOPIC_0000001145894431__p754716511612">11</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.2 "><p id="EN-US_TOPIC_0000001145894431__p205478510615">1.5e+03</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.3 "><p id="EN-US_TOPIC_0000001145894431__p19547155568">5.9e+03</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.4 "><p id="EN-US_TOPIC_0000001145894431__p135478510611">9.5e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.5 "><p id="EN-US_TOPIC_0000001145894431__p2547185267">2.4e+07</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.6 "><p id="EN-US_TOPIC_0000001145894431__p45471752614">1.6e+12</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001145894431__row205471751465"><td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.1 "><p id="EN-US_TOPIC_0000001145894431__p175471951463">12</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.2 "><p id="EN-US_TOPIC_0000001145894431__p554725762">3.0e+03</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.3 "><p id="EN-US_TOPIC_0000001145894431__p14547125266">1.2e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.4 "><p id="EN-US_TOPIC_0000001145894431__p18547175868">1.9e+05</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.5 "><p id="EN-US_TOPIC_0000001145894431__p2547951364">4.8e+07</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.6 "><p id="EN-US_TOPIC_0000001145894431__p135491151568">3.2e+12</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001145894431__row0549185863"><td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.1 "><p id="EN-US_TOPIC_0000001145894431__p95491259619">13</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.2 "><p id="EN-US_TOPIC_0000001145894431__p1918182817811">5.9e+03</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.3 "><p id="EN-US_TOPIC_0000001145894431__p15549145567">2.4e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.4 "><p id="EN-US_TOPIC_0000001145894431__p75491351467">3.8e+05</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.5 "><p id="EN-US_TOPIC_0000001145894431__p10549158615">9.7e+07</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.6 "><p id="EN-US_TOPIC_0000001145894431__p155491955618">6.3e+12</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001145894431__row3549135769"><td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.1 "><p id="EN-US_TOPIC_0000001145894431__p154905165">14</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.2 "><p id="EN-US_TOPIC_0000001145894431__p6549195767">1.2e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.3 "><p id="EN-US_TOPIC_0000001145894431__p135491951617">4.7e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.4 "><p id="EN-US_TOPIC_0000001145894431__p15491951765">7.6e+05</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.5 "><p id="EN-US_TOPIC_0000001145894431__p0549555619">1.9e+08</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.6 "><p id="EN-US_TOPIC_0000001145894431__p75490513614">1.3e+13</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001145894431__row45491151168"><td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.1 "><p id="EN-US_TOPIC_0000001145894431__p8549195663">15</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.2 "><p id="EN-US_TOPIC_0000001145894431__p4549351065">2.4e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.3 "><p id="EN-US_TOPIC_0000001145894431__p105491358611">9.5e+04</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.4 "><p id="EN-US_TOPIC_0000001145894431__p14549851461">1.5e+06</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.5 "><p id="EN-US_TOPIC_0000001145894431__p135496512615">3.9e+08</p>
</td>
<td class="cellrowborder" valign="top" width="16.666666666666664%" headers="mcps1.3.42.6.2.7.1.6 "><p id="EN-US_TOPIC_0000001145894431__p254917520612">2.5e+13</p>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section1785343972518"><h4 class="sectiontitle">hll_default_expthresh</h4><p id="EN-US_TOPIC_0000001145894431__p282873734212"><strong id="EN-US_TOPIC_0000001145894431__b1471694442911">Parameter description</strong>: Specifies the default threshold for switching from the <strong id="EN-US_TOPIC_0000001145894431__b167210315541">explicit</strong> mode to the <strong id="EN-US_TOPIC_0000001145894431__b785113104540">sparse</strong> mode.</p>
<p id="EN-US_TOPIC_0000001145894431__p134807160159"><strong id="EN-US_TOPIC_0000001145894431__b16143163734813">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p442552213427"><strong id="EN-US_TOPIC_0000001145894431__b182371413121814">Value range</strong>: an integer ranging from –1 to 7 <strong id="EN-US_TOPIC_0000001145894431__b5347336204">–1</strong> indicates the auto mode; <strong id="EN-US_TOPIC_0000001145894431__b1135173362018">0</strong> indicates that the <strong id="EN-US_TOPIC_0000001145894431__b635133162014">explicit</strong> mode is skipped; a value from 1 to 7 indicates that the mode is switched when the number of distinct values reaches 2<sup id="EN-US_TOPIC_0000001145894431__sup1236203332011">hll_default_expthresh</sup>.</p>
<p id="EN-US_TOPIC_0000001145894431__p185313942518"><strong id="EN-US_TOPIC_0000001145894431__b1254752973419">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b6548162917346">–1</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section95372411258"><h4 class="sectiontitle">hll_default_sparseon</h4><p id="EN-US_TOPIC_0000001145894431__p753754142515"><strong id="EN-US_TOPIC_0000001145894431__b7640152103514">Parameter description</strong>: Specifies whether to enable the <strong id="EN-US_TOPIC_0000001145894431__b1712145655418">sparse</strong> mode by default.</p>
<p id="EN-US_TOPIC_0000001145894431__p6398647144219"><strong id="EN-US_TOPIC_0000001145894431__b179881839134814">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p17537104112252"><strong id="EN-US_TOPIC_0000001145894431__b66499804">Valid value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706111635">0</strong> and <strong id="EN-US_TOPIC_0000001145894431__b842352706111638">1</strong> <strong id="EN-US_TOPIC_0000001145894431__b62861124103811">0</strong> indicates that the <strong id="EN-US_TOPIC_0000001145894431__b942111106556">sparse</strong> mode is disabled by default. <strong id="EN-US_TOPIC_0000001145894431__b13632018104017">1</strong> indicates that the <strong id="EN-US_TOPIC_0000001145894431__b1072152517552">sparse</strong> mode is enabled by default.</p>
<p id="EN-US_TOPIC_0000001145894431__p7537164112252"><strong id="EN-US_TOPIC_0000001145894431__b934831913594">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b123488198597">1</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section13489114392513"><h4 class="sectiontitle">hll_max_sparse</h4><p id="EN-US_TOPIC_0000001145894431__p134893434251"><strong id="EN-US_TOPIC_0000001145894431__b10914103519400">Parameter description</strong>: Specifies the size of <strong id="EN-US_TOPIC_0000001145894431__b1128613524407">max_sparse</strong>.</p>
<p id="EN-US_TOPIC_0000001145894431__p954735813422"><strong id="EN-US_TOPIC_0000001145894431__b15518104312489">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p164891843112515"><strong id="EN-US_TOPIC_0000001145894431__b35751844115915">Value range</strong>: an integer ranging from –1 to <strong id="EN-US_TOPIC_0000001145894431__b14215253715">INT_MAX</strong></p>
<p id="EN-US_TOPIC_0000001145894431__p848917437259"><strong id="EN-US_TOPIC_0000001145894431__b172868129410">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b8287141211412">–1</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section10636183653718"><h4 class="sectiontitle">enable_compress_hll</h4><p id="EN-US_TOPIC_0000001145894431__p16367361374"><strong id="EN-US_TOPIC_0000001145894431__b143909487910">Parameter description</strong>: Specifies whether to enable memory optimization for HLL.</p>
<p id="EN-US_TOPIC_0000001145894431__p1654718610431"><strong id="EN-US_TOPIC_0000001145894431__b11710943194815">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p18474219104112"><strong id="EN-US_TOPIC_0000001145894431__b58854511693">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul5475919104111"><li id="EN-US_TOPIC_0000001145894431__li13475219104117"><strong id="EN-US_TOPIC_0000001145894431__b156051919234">on</strong> or <strong id="EN-US_TOPIC_0000001145894431__b1332226122318">true</strong> indicates that memory optimization is enabled.</li><li id="EN-US_TOPIC_0000001145894431__li134756199419"><strong id="EN-US_TOPIC_0000001145894431__b17840165217235">off</strong> or <strong id="EN-US_TOPIC_0000001145894431__b340013591231">false</strong> indicates that memory optimization is disabled.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p15636193614372"><strong id="EN-US_TOPIC_0000001145894431__b157910562911">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b157921256496">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section1765913299426"><a name="EN-US_TOPIC_0000001145894431__section1765913299426"></a><a name="section1765913299426"></a><h4 class="sectiontitle">udf_memory_limit</h4><p id="EN-US_TOPIC_0000001145894431__p106541811908"><strong id="EN-US_TOPIC_0000001145894431__b2330163113915">Parameter description</strong>: Controls the maximum physical memory that can be used when each CN or DN executes UDFs.</p>
<p id="EN-US_TOPIC_0000001145894431__p496143171915"><strong id="EN-US_TOPIC_0000001145894431__b16223194415481">Type</strong>: POSTMASTER</p>
<p id="EN-US_TOPIC_0000001145894431__p186572111104"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0085033176_en-us_topic_0059778686_a8791c882938f4e6c9ae407641e405449">Value range</strong>: an integer. The value range is from 200 x 1024 to the value of <a href="dws_04_0893.html#EN-US_TOPIC_0000001145694783__sadc1e0e8c1c246a4a6cad3967deebaad">max_process_memory</a> and the unit is KB.</p>
<p id="EN-US_TOPIC_0000001145894431__p16611811506"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778487_en-us_topic_0058967679_b4605672135217_2">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778487_b842352706154731">200 MB</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section0948171616421"><h4 class="sectiontitle">FencedUDFMemoryLimit</h4><p id="EN-US_TOPIC_0000001145894431__p12890171344316"><strong id="EN-US_TOPIC_0000001145894431__b842352706182822">Parameter description</strong>: Controls the virtual memory used by each fenced udf worker process.</p>
<p id="EN-US_TOPIC_0000001145894431__p1131121704311"><strong id="EN-US_TOPIC_0000001145894431__b24084465489">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p125399121402"><strong id="EN-US_TOPIC_0000001145894431__b578119269104">Suggestion</strong>: You are not advised to set this parameter. You can set <a href="#EN-US_TOPIC_0000001145894431__section1765913299426">udf_memory_limit</a> instead. </p>
<p id="EN-US_TOPIC_0000001145894431__p69576180448"><strong id="EN-US_TOPIC_0000001145894431__b842352706182917">Value range</strong>: an integer. The unit can be KB, MB, or GB. <strong id="EN-US_TOPIC_0000001145894431__b1901530193619">0</strong> indicates that the memory is not limited.</p>
<p id="EN-US_TOPIC_0000001145894431__p5155164174613"><strong id="EN-US_TOPIC_0000001145894431__b939165898">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b329747098">0</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section19591235141915"><h4 class="sectiontitle">UDFWorkerMemHardLimit</h4><p id="EN-US_TOPIC_0000001145894431__p1431814110196"><strong id="EN-US_TOPIC_0000001145894431__b1514105616338">Parameter description</strong>: Specifies the maximum value of <strong id="EN-US_TOPIC_0000001145894431__b6491134353412">fencedUDFMemoryLimit</strong>.</p>
<p id="EN-US_TOPIC_0000001145894431__p10717522111820"><strong id="EN-US_TOPIC_0000001145894431__b644304724819">Type</strong>: POSTMASTER</p>
<p id="EN-US_TOPIC_0000001145894431__p152921643114010"><strong id="EN-US_TOPIC_0000001145894431__b18636195781015">Suggestion</strong>: You are not advised to set this parameter. You can set <a href="#EN-US_TOPIC_0000001145894431__section1765913299426">udf_memory_limit</a> instead. </p>
<p id="EN-US_TOPIC_0000001145894431__p09661737182018"><strong id="EN-US_TOPIC_0000001145894431__b1430583621">Value range</strong>: an integer. The unit can be KB, MB, or GB.</p>
<p id="EN-US_TOPIC_0000001145894431__p74054324251"><strong id="EN-US_TOPIC_0000001145894431__b16102652488">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b191041451481">1 GB</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section867525320283"><h4 class="sectiontitle">pljava_vmoptions</h4><p id="EN-US_TOPIC_0000001145894431__p775465682814"><strong id="EN-US_TOPIC_0000001145894431__b15412056103515">Parameter description</strong>: Specifies the startup parameters for JVMs used by the PL/Java function.</p>
<p id="EN-US_TOPIC_0000001145894431__p8897519171719"><strong id="EN-US_TOPIC_0000001145894431__b136221847164812">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__p815145643020"><strong id="EN-US_TOPIC_0000001145894431__b199811956183512">Value range</strong>: a string, supporting:</p>
<ul id="EN-US_TOPIC_0000001145894431__ul429124714346"><li id="EN-US_TOPIC_0000001145894431__li072243516319">JDK8 JVM startup parameters.</li><li id="EN-US_TOPIC_0000001145894431__li17556164643118">JDK8 JVM system attributes (starting with <strong id="EN-US_TOPIC_0000001145894431__b1242818358161">–D</strong>, for example, <strong id="EN-US_TOPIC_0000001145894431__b3255144213163">–Djava.ext.dirs</strong>).</li><li id="EN-US_TOPIC_0000001145894431__li346747153419">User-defined parameters (starting with <strong id="EN-US_TOPIC_0000001145894431__b1553716486162">–D</strong>, for example, <strong id="EN-US_TOPIC_0000001145894431__b125682051131619">–Duser.defined.option</strong>).</li></ul>
<div class="notice" id="EN-US_TOPIC_0000001145894431__note119961995317"><span class="noticetitle"><img src="public_sys-resources/notice_3.0-en-us.png"> </span><div class="noticebody"><p id="EN-US_TOPIC_0000001145894431__p1419961916539">If <strong id="EN-US_TOPIC_0000001145894431__b17206459163614">pljava_vmoptions</strong> is set to a value beyond the value range, an error will be reported when PL/Java functions are used. </p>
</div></div>
<p id="EN-US_TOPIC_0000001145894431__p2359820163416"><strong id="EN-US_TOPIC_0000001145894431__b19295124823620">Default value</strong>: empty</p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section738715507276"><h4 class="sectiontitle">javaudf_disable_feature</h4><p id="EN-US_TOPIC_0000001145894431__p288924925318"><strong id="EN-US_TOPIC_0000001145894431__b0415135085118">Parameter description</strong>: Specifies the granularity of Java UDF actions.</p>
<p id="EN-US_TOPIC_0000001145894431__p9280937173512"><strong id="EN-US_TOPIC_0000001145894431__b357984515">Type</strong>: SIGHUP</p>
<p id="EN-US_TOPIC_0000001145894431__p107443216285"><strong id="EN-US_TOPIC_0000001145894431__b862573367">Value range</strong>: a string</p>
<ul id="EN-US_TOPIC_0000001145894431__ul14100275345"><li id="EN-US_TOPIC_0000001145894431__li1910057183410"><strong id="EN-US_TOPIC_0000001145894431__b14997153225410">none</strong> indicates that any action specified in other fine-grained parameters is enabled. When this parameter is set together with other parameters, <strong id="EN-US_TOPIC_0000001145894431__b171712516557">none</strong> is invalid.</li><li id="EN-US_TOPIC_0000001145894431__li1110057103411"><strong id="EN-US_TOPIC_0000001145894431__b1736511461555">all</strong> indicates that all Java UDF functions are disabled. This option has the highest priority.</li><li id="EN-US_TOPIC_0000001145894431__li12100972346"><strong id="EN-US_TOPIC_0000001145894431__b379795165615">extdir</strong> indicates that the function of storing dependency JAR packages in a third-party path is disabled.</li><li id="EN-US_TOPIC_0000001145894431__li110014753418"><strong id="EN-US_TOPIC_0000001145894431__b20853111814568">hadoop</strong> indicates that Hadoop functions are disabled.</li><li id="EN-US_TOPIC_0000001145894431__li2010018793414"><strong id="EN-US_TOPIC_0000001145894431__b1018318231312">reflection</strong> indicates that the reflection permission (<strong id="EN-US_TOPIC_0000001145894431__b85851754119">ReflectPermission</strong>) is disabled during the execution of Java UDF functions.</li><li id="EN-US_TOPIC_0000001145894431__li8100472348"><strong id="EN-US_TOPIC_0000001145894431__b1950815345913">loadlibrary</strong> indicates that the dynamic library loading permission (<strong id="EN-US_TOPIC_0000001145894431__b197510512102">loadLibrary</strong>) is disabled during the execution of Java UDF functions.</li><li id="EN-US_TOPIC_0000001145894431__li91006753412"><strong id="EN-US_TOPIC_0000001145894431__b1012042401115">net</strong> indicates that the network permission (<strong id="EN-US_TOPIC_0000001145894431__b46621808129">NetPermission</strong>) is disabled during the execution of Java UDF functions.</li><li id="EN-US_TOPIC_0000001145894431__li01001719341"><strong id="EN-US_TOPIC_0000001145894431__b1444563919127">socket</strong> indicates that the socket permission (<strong id="EN-US_TOPIC_0000001145894431__b12300195219146">SocketPermission</strong>) is disabled during the execution of Java UDF functions.</li><li id="EN-US_TOPIC_0000001145894431__li15100197113415"><strong id="EN-US_TOPIC_0000001145894431__b12407152814152">security</strong> indicates that the security configuration permission (<strong id="EN-US_TOPIC_0000001145894431__b3856114719189">SecurityPermission</strong>) is disabled during the execution of Java UDF functions.</li><li id="EN-US_TOPIC_0000001145894431__li210110713412"><strong id="EN-US_TOPIC_0000001145894431__b19103133731911">classloader</strong> indicates that the <strong id="EN-US_TOPIC_0000001145894431__b545411519208">classLoder</strong> creation permission (<strong id="EN-US_TOPIC_0000001145894431__b644437122019">createClassLoader</strong>) is disabled during the execution of Java UDF functions.</li><li id="EN-US_TOPIC_0000001145894431__li110119773415"><strong id="EN-US_TOPIC_0000001145894431__b33876682111">access_declared_members</strong> indicates that the permission of accessing other declared members (<strong id="EN-US_TOPIC_0000001145894431__b47945176228">accessDeclaredMembers</strong>) is disabled during the execution of Java UDF functions.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p9797195510378"><strong id="EN-US_TOPIC_0000001145894431__b19657332122318">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b1134995312314">extdir,hadoop,reflection,loadlibrary,net,socket,security,classloader,access_declared_members</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section4605202011486"><h4 class="sectiontitle">enable_pbe_optimization</h4><p id="EN-US_TOPIC_0000001145894431__p1162116209481"><strong id="EN-US_TOPIC_0000001145894431__b453379124317">Parameter description</strong>: Specifies whether the optimizer optimizes the query plan for statements executed in Parse Bind Execute (PBE) mode.</p>
<p id="EN-US_TOPIC_0000001145894431__p1570952701717"><strong id="EN-US_TOPIC_0000001145894431__b6808174710482">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__p166018201483"><strong id="EN-US_TOPIC_0000001145894431__b9542154112440">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul144954452277"><li id="EN-US_TOPIC_0000001145894431__li8500154512712"><strong id="EN-US_TOPIC_0000001145894431__b13354135164412">on</strong> indicates that the optimizer optimizes the query plan.</li><li id="EN-US_TOPIC_0000001145894431__li11512114512718"><strong id="EN-US_TOPIC_0000001145894431__b226014273450">off</strong> indicates that the optimization does not optimize the query plan.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p19673182074819"><strong id="EN-US_TOPIC_0000001145894431__b559864202">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b361082460">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section46891552174813"><h4 class="sectiontitle">enable_light_proxy</h4><p id="EN-US_TOPIC_0000001145894431__p13702145274818"><strong id="EN-US_TOPIC_0000001145894431__b11250175084515">Parameter description</strong>: Specifies whether the optimizer optimizes the execution of simple queries on CNs.</p>
<p id="EN-US_TOPIC_0000001145894431__p469693512176"><strong id="EN-US_TOPIC_0000001145894431__b2999154774814">Type</strong>: SUSET</p>
<p id="EN-US_TOPIC_0000001145894431__p5740195212482"><strong id="EN-US_TOPIC_0000001145894431__b1789111246463">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul10758752154819"><li id="EN-US_TOPIC_0000001145894431__li12763105244816"><strong id="EN-US_TOPIC_0000001145894431__b4265203074615">on</strong> indicates that the optimizer optimizes the execution.</li><li id="EN-US_TOPIC_0000001145894431__li207798528488"><strong id="EN-US_TOPIC_0000001145894431__b8422193515464">off</strong> indicates that the optimization does not optimize the execution.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p7791152114813"><strong id="EN-US_TOPIC_0000001145894431__b533384614612">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b13332465465">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section1827711441139"><h4 class="sectiontitle">checkpoint_flush_after</h4><p id="EN-US_TOPIC_0000001145894431__p5282144418132"><strong id="EN-US_TOPIC_0000001145894431__b99511042380">Parameter description</strong>: Specifies the number of consecutive disk pages that the checkpointer writer thread writes before asynchronous flush. In <span id="EN-US_TOPIC_0000001145894431__text1889962024">GaussDB(DWS)</span>, the size of a disk page is 8 KB.</p>
<p id="EN-US_TOPIC_0000001145894431__p27421315144516"><strong id="EN-US_TOPIC_0000001145894431__b18158148134819">Type</strong>: SIGHUP</p>
<p id="EN-US_TOPIC_0000001145894431__p328934441320"><strong id="EN-US_TOPIC_0000001145894431__b158941011193711">Value range</strong>: an integer ranging from 0 to 256. <strong id="EN-US_TOPIC_0000001145894431__b1189471123714">0</strong> indicates that the asynchronous flush function is disabled. For example, if the value is <strong id="EN-US_TOPIC_0000001145894431__b1437811823719">32</strong>, the checkpointer thread continuously writes 32 disk pages (that is, 32 x 8 = 256 KB) before asynchronous flush.</p>
<p id="EN-US_TOPIC_0000001145894431__p15298744171311"><strong id="EN-US_TOPIC_0000001145894431__b823712116532">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b111229195318">32</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section11251245438"><h4 class="sectiontitle">enable_parallel_ddl</h4><p id="EN-US_TOPIC_0000001145894431__p186209614439"><strong id="EN-US_TOPIC_0000001145894431__b810103618116">Parameter description</strong>: Controls whether multiple CNs can concurrently perform DDL operations on the same database object.</p>
<p id="EN-US_TOPIC_0000001145894431__p104563513431"><strong id="EN-US_TOPIC_0000001145894431__b1468514814483">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p146306604316"><strong id="EN-US_TOPIC_0000001145894431__b428230858">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul1984619152455"><li id="EN-US_TOPIC_0000001145894431__li3848171554517"><strong id="EN-US_TOPIC_0000001145894431__b1156812482113">on</strong> indicates that DDL operations can be performed safely and that no distributed deadlock occurs.</li><li id="EN-US_TOPIC_0000001145894431__li48518155454"><strong id="EN-US_TOPIC_0000001145894431__b203511789126">off</strong> indicates that DDL operations cannot be performed safely and that distributed deadlocks may occur.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p1363476194311"><strong id="EN-US_TOPIC_0000001145894431__b1104974565">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b624001464">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section29017124241"><h4 class="sectiontitle">show_acce_estimate_detail</h4><p id="EN-US_TOPIC_0000001145894431__p119811252420"><strong id="EN-US_TOPIC_0000001145894431__b39830174137">Parameter description</strong>: When the <span id="EN-US_TOPIC_0000001145894431__text199466072">GaussDB(DWS)</span> cluster is accelerated (<a href="dws_04_0945.html#EN-US_TOPIC_0000001099134808__section13787157164412">acceleration_with_compute_pool</a> is set to <strong id="EN-US_TOPIC_0000001145894431__b111314815134">on</strong>), specifies whether the <strong id="EN-US_TOPIC_0000001145894431__b1593711104144">EXPLAIN</strong> statement displays the evaluation information about execution plan pushdown to computing Node Groups. The evaluation information is generally used by O&amp;M personnel during maintenance, and it may affect the output display of the <strong id="EN-US_TOPIC_0000001145894431__b872662111611">EXPLAIN</strong> statement. Therefore, this parameter is disabled by default. The evaluation information is displayed only if the <strong id="EN-US_TOPIC_0000001145894431__b156850412165">verbose</strong> option of the <strong id="EN-US_TOPIC_0000001145894431__b6881646191612">EXPLAIN</strong> statement is enabled.</p>
<p id="EN-US_TOPIC_0000001145894431__p39415541438"><strong id="EN-US_TOPIC_0000001145894431__b1822194994810">Type</strong>: USERSET</p>
<p id="EN-US_TOPIC_0000001145894431__p710810127247"><strong id="EN-US_TOPIC_0000001145894431__b1289084112710">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul1411511214248"><li id="EN-US_TOPIC_0000001145894431__li91171112172414"><strong id="EN-US_TOPIC_0000001145894431__b86081331192418">on</strong> indicates that the evaluation information is displayed in the output of the <strong id="EN-US_TOPIC_0000001145894431__b9422184052412">EXPLAIN</strong> statement.</li><li id="EN-US_TOPIC_0000001145894431__li91221212192418"><strong id="EN-US_TOPIC_0000001145894431__b11231122112404">off</strong> indicates that the evaluation information is not displayed in the output of the <strong id="EN-US_TOPIC_0000001145894431__b12321921124019">EXPLAIN</strong> statement.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p512641262419"><strong id="EN-US_TOPIC_0000001145894431__en-us_topic_0059778871_en-us_topic_0058967732_b46080773_10">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b842352706145110">off</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section157265302582"><h4 class="sectiontitle">support_batch_bind</h4><p id="EN-US_TOPIC_0000001145894431__p15726830175817"><strong id="EN-US_TOPIC_0000001145894431__b925091310513">Parameter description</strong>: Specifies whether to batch bind and execute PBE statements through interfaces such as JDBC, ODBC, and Libpq.</p>
<p id="EN-US_TOPIC_0000001145894431__p19511345444"><strong id="EN-US_TOPIC_0000001145894431__b132007496483">Type</strong>: SIGHUP</p>
<p id="EN-US_TOPIC_0000001145894431__p11727103012587"><strong id="EN-US_TOPIC_0000001145894431__b1427390990">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul77271530105814"><li id="EN-US_TOPIC_0000001145894431__li207271330165815"><strong id="EN-US_TOPIC_0000001145894431__b1566944515114">on</strong> indicates that batch binding and execution are used.</li><li id="EN-US_TOPIC_0000001145894431__li15727113085814"><strong id="EN-US_TOPIC_0000001145894431__b12251816185211">off</strong> indicates that batch binding and execution are not used.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p272753095815"><strong id="EN-US_TOPIC_0000001145894431__b1089053689">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b95211247">on</strong></p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145894431__section82231820131319"><h4 class="sectiontitle">enable_immediate_interrupt</h4><p id="EN-US_TOPIC_0000001145894431__p8223122001311"><strong id="EN-US_TOPIC_0000001145894431__b93068012320">Parameter description</strong>: Specifies whether the execution of the current statement or session can be immediately interrupted in the signal processing function.</p>
<p id="EN-US_TOPIC_0000001145894431__p192242203134"><strong id="EN-US_TOPIC_0000001145894431__b107261499298">Type</strong>: SIGHUP</p>
<p id="EN-US_TOPIC_0000001145894431__p1222432091310"><strong id="EN-US_TOPIC_0000001145894431__b18578171515293">Value range</strong>: Boolean</p>
<ul id="EN-US_TOPIC_0000001145894431__ul1722411206132"><li id="EN-US_TOPIC_0000001145894431__li722492014130"><strong id="EN-US_TOPIC_0000001145894431__b71371629142914">on</strong> indicates that the execution of the current statement or session can be immediately interrupted in the signal processing function.</li><li id="EN-US_TOPIC_0000001145894431__li722492014136"><strong id="EN-US_TOPIC_0000001145894431__b19499103520293">off</strong> indicates that the execution of the current statement or session cannot be immediately interrupted in the signal processing function.</li></ul>
<p id="EN-US_TOPIC_0000001145894431__p16224162071313"><strong id="EN-US_TOPIC_0000001145894431__b363334012914">Default value</strong>: <strong id="EN-US_TOPIC_0000001145894431__b36402406296">off</strong></p>
<div class="note" id="EN-US_TOPIC_0000001145894431__note342119371718"><img src="public_sys-resources/note_3.0-en-us.png"><span class="notetitle"> </span><div class="notebody"><p id="EN-US_TOPIC_0000001145894431__p1973133194016">Exercise caution when setting this parameter to <strong id="EN-US_TOPIC_0000001145894431__b990015017339">on</strong>. If the execution of the current statement or session can be immediately interrupted in the signal processing function, the execution of some key processes may be interrupted, causing the failure to release the global lock in the system. It is recommended that this parameter be set to <strong id="EN-US_TOPIC_0000001145894431__b1743293183720">on</strong> only during system debugging or fault prevention.</p>
</div></div>
</div>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_04_0883.html">GUC Parameters</a></div>
</div>
</div>
View Git Blame Copy Permalink