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Lu, Huayi e6fa411af0 DWS DEV 830.201 version 
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com>
Co-authored-by: Lu, Huayi <luhuayi@huawei.com>
Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
2024-05-16 07:24:04 +00:00

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<a name="EN-US_TOPIC_0000001233761803"></a><a name="EN-US_TOPIC_0000001233761803"></a>
<h1 class="topictitle1">PG_THREAD_WAIT_STATUS</h1>
<div id="body8662426"><p id="EN-US_TOPIC_0000001233761803__a5554757c1a0a4e138ece1127f70a2afd"><strong id="EN-US_TOPIC_0000001233761803__b842352706105440">PG_THREAD_WAIT_STATUS</strong> allows you to test the block waiting status about the backend thread and auxiliary thread of the current instance.</p>
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001233761803__tc1eb0361455748848cddf86faf056065" frame="border" border="1" rules="all"><caption><b>Table 1 </b>PG_THREAD_WAIT_STATUS columns</caption><thead align="left"><tr id="EN-US_TOPIC_0000001233761803__r4eef275030cb48b2941135b4c1992fd2"><th align="left" class="cellrowborder" valign="top" width="19.040000000000003%" id="mcps1.3.2.2.4.1.1"><p id="EN-US_TOPIC_0000001233761803__a5186495845b64861ac7e2732178353b5">Name</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="12.85%" id="mcps1.3.2.2.4.1.2"><p id="EN-US_TOPIC_0000001233761803__a7c2e585e6fb64960abcf653ae265e793">Type</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="68.11%" id="mcps1.3.2.2.4.1.3"><p id="EN-US_TOPIC_0000001233761803__afae64c14a4914bc786e851993ed7b5c6">Description</p>
</th>
</tr>
</thead>
<tbody><tr id="EN-US_TOPIC_0000001233761803__r272bd8fe0de24ebabc6ccaf0fa7c3172"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__a5313b111dbb04081b26c089e60d73b4e">node_name</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__abc5f3937999b46769bc9e2cfc94f0930">text</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__ac1313e24915e4e2ca9148466a239b781">Current node name</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r321baea93cd14a4b91cad5702599f3b8"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__ab2456725fdc048a3833009c7a36110f0">db_name</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__a1bd1b741d70648a6b856849be816c3bd">text</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__a3029cbb1a3c54df8a7ff981e29ee5c9e">Database name</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r995c106cd6384b10a82e2bb5c3419cc4"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__a534622117f1c490db6043ea1938b086b">thread_name</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__ad52371acffed4cb285a3244051e258d8">text</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__add8e4c6d405b4020a8d965b3c07bcb89">Thread name</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__reb3a90d1c2aa45168992ebf024359857"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__a6fa96fdb4d2f47eb8d20c1da73018b3d">query_id</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__af653d3f9df03467c867d4d7b1abbca93">bigint</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__a3630fdc18f9640e0a8e9b1873b268756">Query ID. It is equivalent to <strong id="EN-US_TOPIC_0000001233761803__b842352706144235">debug_query_id</strong>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r5f6021bbe0914f7fa61662632397d9ed"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__aaa9a2e2bd19148028ef0f185231059f9">tid</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__a7d5ac290f8a941ba8a45b833e06e2d57">bigint</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__a31aca088fb914d06a4bc51a499f010f8">Thread ID of the current thread</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__rb06d7687432f4858b5bb8f64b45bd9b8"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__afbb6c83914b743498b7db95d4d5ed793">lwtid</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__afa678ca850d7479690fc1d4dcef7cb25">integer</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__ace8324c86bf34aaaaaf202d3b2f15616">Lightweight thread ID of the current thread</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__rf0a9a6a7de174f998f484962943b88d8"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__a297d91839dee452ea7d0df64492544f0">ptid</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__a6c5e107fb211484bbd1730d482e5e1de">integer</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__a18574b6a07ab44df9b55066e70c8d6db">Parent thread of the streaming thread</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__ra6aa1f8e0c3540f6a52d906f44326a2e"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__adc6d625a053645daab7bce16f9eddcc7">tlevel</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__a3299ed2dd0164f778663486036193bba">integer</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__abd7c683559004959824a0491862c8630">Level of the streaming thread</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r425ff9d1799045dc8f3187396243246d"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__a3fce0e14848549888d134e8875172731">smpid</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__ad5cc9d712bad46b3bc2d1aff83c6d1ed">integer</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__ad2f01d133f54487086f57a385e439f26">Concurrent thread ID</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r40439ac3a24745428adf41d43bc1589e"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__ad10342389b5c45999f1ad13abffbf6d0">wait_status</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__aefbf6d4871d943b39a4e0901362d1b8e">text</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__a7e1d75edcf09483191de0ef96aa326ce">Waiting status of the current thread. For details about the waiting status, see <a href="#EN-US_TOPIC_0000001233761803__t2e88141821ac42158405ff5eea1d7285">Table 2</a>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row10717192619111"><td class="cellrowborder" valign="top" width="19.040000000000003%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001233761803__p771742617112">wait_event</p>
</td>
<td class="cellrowborder" valign="top" width="12.85%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001233761803__p17191626718">text</p>
</td>
<td class="cellrowborder" valign="top" width="68.11%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001233761803__p971918266112">If <strong id="EN-US_TOPIC_0000001233761803__b13600138154111">wait_status</strong> is <strong id="EN-US_TOPIC_0000001233761803__b335031715411">acquire lock</strong>, <strong id="EN-US_TOPIC_0000001233761803__b13553101917415">acquire lwlock</strong>, or <strong id="EN-US_TOPIC_0000001233761803__b16724152184115">wait io</strong>, this column describes the lock, lightweight lock, and I/O information, respectively. If <strong id="EN-US_TOPIC_0000001233761803__b10990656134118">wait_status</strong> is not any of the three values, this column is empty.</p>
</td>
</tr>
</tbody>
</table>
</div>
<p id="EN-US_TOPIC_0000001233761803__a2557f82ffc1b4f898250b35660b3e7de">The waiting statuses in the <strong id="EN-US_TOPIC_0000001233761803__b842352706153657">wait_status</strong> column are as follows:</p>
<div class="tablenoborder"><a name="EN-US_TOPIC_0000001233761803__t2e88141821ac42158405ff5eea1d7285"></a><a name="t2e88141821ac42158405ff5eea1d7285"></a><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001233761803__t2e88141821ac42158405ff5eea1d7285" frame="border" border="1" rules="all"><caption><b>Table 2 </b>Waiting status list</caption><thead align="left"><tr id="EN-US_TOPIC_0000001233761803__r93323c5804d74a69961ffd52197b33bb"><th align="left" class="cellrowborder" valign="top" width="43.419999999999995%" id="mcps1.3.4.2.3.1.1"><p id="EN-US_TOPIC_0000001233761803__a2e2a9b6683604560b08eaecb36dee33a">Value </p>
</th>
<th align="left" class="cellrowborder" valign="top" width="56.58%" id="mcps1.3.4.2.3.1.2"><p id="EN-US_TOPIC_0000001233761803__a88c9abc490414015827584e4cad779b4">Description</p>
</th>
</tr>
</thead>
<tbody><tr id="EN-US_TOPIC_0000001233761803__r94bf6d89774d40048b45ca1ff79400f9"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__afa0f5c40d96340978814119421d21c7e">none</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a30d555da54e44cfa9670495e0813baca">Waiting for no event</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__re0563580df9d487aa40f05fe5a218b15"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a707f25e454254ef796af9fc52a356a28">acquire lock</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a0a401f41f8f544f8afaf028e3bd841e8">Waiting for locking until the locking succeeds or times out</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1528317111316"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p20283711135">acquire lwlock</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p828318115314">Waiting for a lightweight lock</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row108721517183113"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p168726179319">wait io</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1287381703115">Waiting for I/O completion</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r1093b877606f421dac4419b58f57f2f2"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a41c0511df78b47529ea3dd0d45ed98f6">wait cmd</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a9d68be50c5c74d1fb09ea25487dd8e2c">Waiting for network communication packet read to complete</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r174aeed51889471db15e570485a0346c"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__ae70135d065f94575b94b3050232283b3">wait pooler get conn</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a957e7279a8de4d88b70a48e58727e4bd">Waiting for pooler to obtain the connection</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__re03eaa4d416646fab5abacff71c9231d"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a00dd880ee3c1442785bd704b0e71840a">wait pooler abort conn</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a48a83a2a3c314d1d9b647688c881a5ce">Waiting for pooler to terminate the connection</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__rb25a2d3fdc864c7c880d0c78458dabeb"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a48ee5b6b658b455aa80266f2ecd57c71">wait pooler clean conn</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a4a05fc296557482baf5403ba862f97ce">Waiting for pooler to clear connections</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row19272759112010"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p92736598202">pooler create conn: [nodename], total N</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2027355952016">Waiting for the pooler to set up a connection. The connection is being established with the node specified by <em id="EN-US_TOPIC_0000001233761803__i161261041163510">nodename</em>, and there are <em id="EN-US_TOPIC_0000001233761803__i11127541133511">N</em> connections waiting to be set up.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r5abcd9fcc3764afabe13780b2b6dd307"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a55ec981567374e6689c9ec9aace327c7">get conn</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a40cd96036b9e4c13b7ab8723fa65fb7e">Obtaining the connection to other nodes</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r1a28e1f8b8e04148875e8e4392ed349e"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a0c31a3939a6c48cbaf397aa8fa843443">set cmd: [nodename]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__aa31a76ca9bf1444dadd81b7499e0cd18">Waiting for running the <strong id="EN-US_TOPIC_0000001233761803__b1014211585350">SET</strong>, <strong id="EN-US_TOPIC_0000001233761803__b18143205816351">RESET</strong>, <strong id="EN-US_TOPIC_0000001233761803__b1914465823518">TRANSACTION BLOCK LEVEL PARA SET</strong>, or <strong id="EN-US_TOPIC_0000001233761803__b4145658193512">SESSION LEVEL PARA SET</strong> statement on the connection. The statement is being executed on the node specified by <em id="EN-US_TOPIC_0000001233761803__i31541658173518">nodename</em>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r269155058e4f40ebaa7bff800cd70482"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a83e0dd567f6e4d069e2910a5c1a165ac">cancel query</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a03ec630a89dd4f7398cac313b27ca36d">Canceling the SQL statement that is being executed through the connection</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__ra8f0725eab644b64a6163f8d85c02996"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__ac4d44244dfe045cc9fc2268a08f70feb">stop query</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__abb7e1edc88f349b9a579e3a5574544f7">Stopping the query that is being executed through the connection</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r0f83de5156984dfbb5ce8bf57ad326ee"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a3412d9b2b7ea4ccab869ad13fec1f2ea">wait node: [nodename](plevel), total N, [phase]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p577573613228">Waiting for receiving the data from a connected node. The thread is waiting for the data from the plevel thread of the node specified by <em id="EN-US_TOPIC_0000001233761803__i76014329375">nodename</em>. The data of <em id="EN-US_TOPIC_0000001233761803__i360203283719">N</em> connections is waiting to be returned. If <em id="EN-US_TOPIC_0000001233761803__i9302165083711">phase</em> is included, the possible phases are as follows:</p>
<ul id="EN-US_TOPIC_0000001233761803__ul21682503315"><li id="EN-US_TOPIC_0000001233761803__li151691850123119"><strong id="EN-US_TOPIC_0000001233761803__b1176915613716">begin</strong>: The transaction is being started.</li><li id="EN-US_TOPIC_0000001233761803__li20891121213325"><strong id="EN-US_TOPIC_0000001233761803__b145392588376">commit</strong>: The transaction is being committed.</li><li id="EN-US_TOPIC_0000001233761803__li427636103219"><strong id="EN-US_TOPIC_0000001233761803__b16667125919372">rollback</strong>: The transaction is being rolled back.</li></ul>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r8e6b7e13ea364deea50031494b6ac1eb"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a86722d696a3d4976b1a757bea4455a19">wait transaction sync: xid</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a76b7bd991c6f4226b38c56ec5031988f">Waiting for synchronizing the transaction specified by <em id="EN-US_TOPIC_0000001233761803__i11141141673817">xid</em></p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r1d85424b0f434461baf464c80677d5d7"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a64abec6bae7b48bb872cce48546f0cb8">wait wal sync</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a2396da2f55c6463f98d0d96cfe03042c">Waiting for the completion of wal log of synchronization from the specified LSN to the standby instance</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__rcdb6b5051f344fb69767f65b0d04b26a"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a379c8c61c41543e9861897b5f8204228">wait data sync</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a49d2fd73b590495fa1ec787f1ccd9997">Waiting for the completion of data page synchronization to the standby instance</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r09f272615ee64bb18a9276f4017a2007"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__a194727cd888a48d3a8a08780910515e2">wait data sync queue</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a4bb07e3b31e04626bc339424bee01ceb">Waiting for putting the data pages that are in the row storage or the CU in the column storage into the synchronization queue</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__rffdcd5e70fcf4730bf8bc1d8deb80b40"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__ac9bcf9bc92c84571848e15705c51dc66">flush data: [nodename](plevel), [phase]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__af042f5d754c24ae8819d02f0b1b25255">Waiting for sending data to the plevel thread of the node specified by <em id="EN-US_TOPIC_0000001233761803__i33067416384">nodename</em>. If <em id="EN-US_TOPIC_0000001233761803__i9253545173820">phase</em> is included, the possible phase is <strong id="EN-US_TOPIC_0000001233761803__b1925494513817">wait quota</strong>, indicating that the current communication flow is waiting for the quota value.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__ra9d39e9c904b42018337991e91d59c3c"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__aa1fe6644b2774e62b579775f05db9944">stream get conn: [nodename], total N</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a5b91354ff79f4e0eaaba4943e2a22562">Waiting for connecting to the consumer object of the node specified by <em id="EN-US_TOPIC_0000001233761803__i243715315381">nodename</em> when the stream flow is initialized. There are <em id="EN-US_TOPIC_0000001233761803__i64388531380">N</em> consumers waiting to be connected.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r9ef4de702bd84c928f0c9f61a3562f5c"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__adf0ca8c8163149bc8ad7c9eeef7da961">wait producer ready: [nodename](plevel), total N</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__a3b0c34c65cec40d5917de866ca319197">Waiting for each producer to be ready when the stream flow is initialized. The thread is waiting for the procedure of the plevel thread on the <em id="EN-US_TOPIC_0000001233761803__i46656453918">nodename</em> node to be ready. There are <em id="EN-US_TOPIC_0000001233761803__i66665403913">N</em> producers waiting to be ready.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__r7c19ddff43224301b1142f79a9817a5b"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__ab6387a74cdc54e0e830e248bcecc7b6b">synchronize quit</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__acb2574b30e7e48d59d98686340505649">Waiting for the threads in the stream thread group to quit when the steam plan ends</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__rb18bd539b2a74618ab99637e1e2cab99"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__ad918d5fd48d94ecf9a6d11fc9ac1e40a">nodegroup destroy</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__af4931c58e1854bdd935646b2e73f3634">Waiting for destroying the stream node group when the steam plan ends</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row14767655113316"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p137674550338">wait active statement</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1176715558335">Waiting for job execution under resource and load control.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1370934220377"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p19710144216373">wait global queue</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p20710144216376">Waiting for job execution. The job is queuing in the global queue.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row13491656153616"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p94911456173611">wait respool queue</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p54911256113618">Waiting for job execution. The job is queuing in the resource pool.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row12554161203812"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p755481113817">wait ccn queue</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1755491103810">Waiting for job execution. The job is queuing on the central coordinator node (CCN).</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row183383224266"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p18339152252617">gtm connect</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1433952217261">Waiting for connecting to GTM.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1698142682617"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p269913262265">gtm get gxid</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1369992614265">Wait for obtaining xids from GTM.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row15998154710261"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1099964722615">gtm get snapshot</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1999914471265">Wait for obtaining transaction snapshots from GTM.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row499954782611"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p15999747102612">gtm begin trans</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p139997476264">Waiting for GTM to start a transaction.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1751165317264"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1151115312610">gtm commit trans</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p20521353112613">Waiting for GTM to commit a transaction.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1752135382610"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p95245392618">gtm rollback trans</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p85285315262">Waiting for GTM to roll back a transaction.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row19789111711275"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p12790141742712">gtm create sequence</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p11790417192714">Waiting for GTM to create a sequence.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row279041782719"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1379041713279">gtm alter sequence</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p5790917182719">Waiting for GTM to modify a sequence.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row879081772712"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1979171762715">gtm get sequence val</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1279131720276">Waiting for obtaining the next value of a sequence from GTM.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row18791171711278"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1179115173276">gtm set sequence val</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p9791917162712">Waiting for GTM to set a sequence value.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row9791617182718"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p37917176273">gtm drop sequence</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p7791417202716">Waiting for GTM to delete a sequence.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row9791191714271"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p177921178270">gtm rename sequece</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p18792617112712">Waiting for GTM to rename a sequence.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row19650172892719"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1865082892710">analyze: [relname], [phase]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2065072872717">The thread is doing <strong id="EN-US_TOPIC_0000001233761803__b19416217124012">ANALYZE</strong> to the <em id="EN-US_TOPIC_0000001233761803__i241841713402">relname</em> table. If <em id="EN-US_TOPIC_0000001233761803__i4905132304014">phase</em> is included, the possible phase is <strong id="EN-US_TOPIC_0000001233761803__b17906122314408">autovacuum</strong>, indicating that the database automatically enables the AutoVacuum thread to execute <strong id="EN-US_TOPIC_0000001233761803__b390762334016">ANALYZE</strong>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row13650172842711"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p165012816279">vacuum: [relname], [phase]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p10650132810279">The thread is doing <strong id="EN-US_TOPIC_0000001233761803__b137872037184019">VACUUM</strong> to the <em id="EN-US_TOPIC_0000001233761803__i6788163712401">relname</em> table. If <em id="EN-US_TOPIC_0000001233761803__i166219402405">phase</em> is included, the possible phase is <strong id="EN-US_TOPIC_0000001233761803__b166315404403">autovacuum</strong>, indicating that the database automatically enables the AutoVacuum thread to execute <strong id="EN-US_TOPIC_0000001233761803__b186641409405">VACUUM</strong>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row8650828162716"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p26501328142718">vacuum full: [relname]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p19651102882715">The thread is doing <strong id="EN-US_TOPIC_0000001233761803__b4815174764020">VACUUM FULL</strong> to the <em id="EN-US_TOPIC_0000001233761803__i188177477403">relname</em> table.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row11651828112718"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p186511828192716">create index</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p26511328192717">An index is being created.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row10651028172712"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p16651162872712">HashJoin - [ build hash | write file ]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p146511528162711">The <strong id="EN-US_TOPIC_0000001233761803__b98641566409">HashJoin</strong> operator is being executed. In this phase, you need to pay attention to the execution time-consuming.</p>
<ul id="EN-US_TOPIC_0000001233761803__ul10627844133118"><li id="EN-US_TOPIC_0000001233761803__li11627444123110"><strong id="EN-US_TOPIC_0000001233761803__b0334451413">build hash</strong>: The <strong id="EN-US_TOPIC_0000001233761803__b1335125204119">HashJoin</strong> operator is creating a hash table.</li><li id="EN-US_TOPIC_0000001233761803__li22124773114"><strong id="EN-US_TOPIC_0000001233761803__b5764171517417">write file</strong>: The <strong id="EN-US_TOPIC_0000001233761803__b18766151534113">HashJoin</strong> operator is writing data to disks.</li></ul>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row565102819272"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1651142818270">HashAgg - [ build hash | write file ]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p165102818277">The <strong id="EN-US_TOPIC_0000001233761803__b1359571784119">HashAgg</strong> operator is being executed. In this phase, you need to pay attention to the execution time-consuming.</p>
<ul id="EN-US_TOPIC_0000001233761803__ul152447611329"><li id="EN-US_TOPIC_0000001233761803__li112445663211"><strong id="EN-US_TOPIC_0000001233761803__b74820276416">build hash</strong>: The <strong id="EN-US_TOPIC_0000001233761803__b15484182744113">HashAgg</strong> operator is creating a hash table.</li><li id="EN-US_TOPIC_0000001233761803__li856351223213"><strong id="EN-US_TOPIC_0000001233761803__b66373299419">write file</strong>: The <strong id="EN-US_TOPIC_0000001233761803__b363842994116">HashAgg</strong> operator is writing data to disks.</li></ul>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row186511028192718"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1465252814278">HashSetop - [build hash | write file ]</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p16652192872711">The <strong id="EN-US_TOPIC_0000001233761803__b819483124114">HashSetop</strong> operator is being executed. In this phase, you need to pay attention to the execution time-consuming.</p>
<ul id="EN-US_TOPIC_0000001233761803__ul5196135473214"><li id="EN-US_TOPIC_0000001233761803__li619617548328"><strong id="EN-US_TOPIC_0000001233761803__b34219354419">build hash</strong>: The <strong id="EN-US_TOPIC_0000001233761803__b19423173514111">HashSetop</strong> operator is creating a hash table.</li><li id="EN-US_TOPIC_0000001233761803__li1218517563324"><strong id="EN-US_TOPIC_0000001233761803__b74343824115">write file</strong>: The <strong id="EN-US_TOPIC_0000001233761803__b1644133818413">HashSetop</strong> operator is writing data to disks.</li></ul>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1865282815271"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p16522280274">Sort | Sort - write file</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p19652182882719">The <strong id="EN-US_TOPIC_0000001233761803__b1292411394419">Sort</strong> operator is being executed. <strong id="EN-US_TOPIC_0000001233761803__b19261239184113">write file</strong> indicates that the <strong id="EN-US_TOPIC_0000001233761803__b492863904112">Sort</strong> operator is writing data to disks.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1865242818275"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1965218287273">Material | Material - write file</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p16652112842710">The <strong id="EN-US_TOPIC_0000001233761803__b888584644116">Material</strong> operator is being executed. <strong id="EN-US_TOPIC_0000001233761803__b3888184614116">write file</strong> indicates that the <strong id="EN-US_TOPIC_0000001233761803__b198901946124115">Material</strong> operator is writing data to disks.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row111714825411"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p31898145413">wait sync consumer next step</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p9187895419">The consumer (receive end) synchronously waits for the next iteration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1086718149559"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p188671714195518">wait sync producer next step</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p186711414559">The producer (transmit end) synchronously waits for the next iteration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row829956134711"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p153008620479">wait agent release</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1946112266535">The current agent is being released (supported by 8.1.2 and later versions).</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row7727193364814"><td class="cellrowborder" valign="top" width="43.419999999999995%" headers="mcps1.3.4.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p97271533154815">wait stream task</p>
</td>
<td class="cellrowborder" valign="top" width="56.58%" headers="mcps1.3.4.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1172743316482">The stream thread is waiting for being reused (supported by 8.1.2 and later versions).</p>
</td>
</tr>
</tbody>
</table>
</div>
<p id="EN-US_TOPIC_0000001233761803__p17289333181513">If <strong id="EN-US_TOPIC_0000001233761803__b17336102501314">wait_status</strong> is <strong id="EN-US_TOPIC_0000001233761803__b8866162616135">acquire lwlock</strong>, <strong id="EN-US_TOPIC_0000001233761803__b18724229151314">acquire lock</strong>, or <strong id="EN-US_TOPIC_0000001233761803__b269415319133">wait io</strong>, there is an event performing I/O operations or waiting for obtaining the corresponding lightweight lock or transaction lock.</p>
<p id="EN-US_TOPIC_0000001233761803__p198221729143117">The following table describes the corresponding wait events when <strong id="EN-US_TOPIC_0000001233761803__b8446113918459">wait_status</strong> is <strong id="EN-US_TOPIC_0000001233761803__b1445104211453">acquire lwlock</strong>. (If <strong id="EN-US_TOPIC_0000001233761803__b39001813124617">wait_event</strong> is <strong id="EN-US_TOPIC_0000001233761803__b866541534610">extension</strong>, the lightweight lock is dynamically allocated and is not monitored.)</p>
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001233761803__table69691424165713" frame="border" border="1" rules="all"><caption><b>Table 3 </b>List of wait events corresponding to lightweight locks</caption><thead align="left"><tr id="EN-US_TOPIC_0000001233761803__row2969202485714"><th align="left" class="cellrowborder" valign="top" width="34.449999999999996%" id="mcps1.3.7.2.3.1.1"><p id="EN-US_TOPIC_0000001233761803__p0094712340">wait_event</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="65.55%" id="mcps1.3.7.2.3.1.2"><p id="EN-US_TOPIC_0000001233761803__p120747143414">Description</p>
</th>
</tr>
</thead>
<tbody><tr id="EN-US_TOPIC_0000001233761803__row9969224185715"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p18785134210012">ShmemIndexLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p127852429012">Used to protect the primary index table, a hash table, in shared memory</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row10970172418579"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p15785204215014">OidGenLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p177859421406">Used to prevent different threads from generating the same OID</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row99701824165713"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p2786144212014">XidGenLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p19786114210010">Used to prevent two transactions from obtaining the same XID</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row69702240572"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p07861421803">ProcArrayLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2786194219018">Used to prevent concurrent access to or concurrent modification on the ProcArray shared array</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1495681518590"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p187872421004">SInvalReadLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p778724218012">Used to prevent concurrent execution with invalid message deletion</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1195820151591"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p13787342102">SInvalWriteLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p678711424018">Used to prevent concurrent execution with invalid message write and deletion</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1795841545911"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1278884219012">WALInsertLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p3788242707">Used to prevent concurrent execution with WAL insertion</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row16959171515914"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p18788124214016">WALWriteLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1078813421707">Used to prevent concurrent write from a WAL buffer to a disk</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row264912312593"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p87883426017">ControlFileLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p197891342003">Used to prevent concurrent read/write or concurrent write/write on the <strong id="EN-US_TOPIC_0000001233761803__b1377241113213">pg_control</strong> file</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row965072313594"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p9789142601">CheckpointLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p97891427015">Used to prevent multi-checkpoint concurrent execution</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row4692128115919"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p47890421301">CLogControlLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1379094219016">Used to prevent concurrent access to or concurrent modification on the Clog control data structure</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row769318283592"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p197904427019">MultiXactGenLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p7791842507">Used to allocate a unique MultiXact ID in serial mode</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row4694152816591"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p57912420017">MultiXactOffsetControlLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p6791442702">Used to prevent concurrent read/write or concurrent write/write on <strong id="EN-US_TOPIC_0000001233761803__b284154614418">pg_multixact/offset</strong></p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row11694152819593"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1479184211012">MultiXactMemberControlLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p479124219013">Used to prevent concurrent read/write or concurrent write/write on <strong id="EN-US_TOPIC_0000001233761803__b117471149114419">pg_multixact/members</strong></p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row669462817599"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p37917421402">RelCacheInitLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p779217421104">Used to add a lock before any operations are performed on the <strong id="EN-US_TOPIC_0000001233761803__b19128101111112">init</strong> file when messages are invalid</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row13695122845912"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8792124215018">CheckpointerCommLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p679294210018">Used to send file flush requests to a checkpointer. The request structure needs to be inserted to a request queue in serial mode.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row96956281594"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p10792242906">TwoPhaseStateLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p197921942405">Used to prevent concurrent access to or modification on two-phase information sharing arrays</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row136951428175911"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p57921421708">TablespaceCreateLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p147925420019">Used to check whether a tablespace already exists</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row14696172825918"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p15793742205">BtreeVacuumLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p679317424011">Used to prevent <strong id="EN-US_TOPIC_0000001233761803__b18540153513330">VACUUM</strong> from clearing pages that are being used by B-tree indexes</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row175461537145911"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p187937425012">AutovacuumLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p37931042309">Used to access the autovacuum worker array in serial mode</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row85461437145915"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p137931425010">AutovacuumScheduleLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p127934422010">Used to distribute tables requiring <strong id="EN-US_TOPIC_0000001233761803__b15917114515143">VACUUM</strong> in serial mode</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row354733755911"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p37945421905">SyncScanLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1794114213017">Used to determine the start position of a relfilenode during heap scanning</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row195479376598"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p879424215011">NodeTableLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p157954421606">Used to protect a shared structure that stores CN and DN information</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row175471037115913"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1879514213013">PoolerLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1879515429015">Used to prevent two threads from simultaneously obtaining the same connection from a connection pool</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row35482037185919"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1679518423015">RelationMappingLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1279584211010">Used to wait for the mapping file between system catalogs and storage locations to be updated</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row55488379593"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1779534212012">AsyncCtlLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p07954428010">Used to prevent concurrent access to or concurrent modification on the sharing notification status</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row6548163712592"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p77962424012">AsyncQueueLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p779612423012">Used to prevent concurrent access to or concurrent modification on the sharing notification queue</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1754916376598"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p57961542105">SerializableXactHashLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p3796742908">Used to prevent concurrent read/write or concurrent write/write on a sharing structure for serializable transactions</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row15549113715915"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p279610421606">SerializableFinishedListLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p7796114216016">Used to prevent concurrent read/write or concurrent write/write on a shared linked list for completed serial transactions</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row2549153710592"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p11797134210017">SerializablePredicateLockListLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p197978421703">Used to protect a linked list of serializable transactions that have locks</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row85501037165912"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p779774210012">OldSerXidLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p5797184218016">Used to protect a structure that records serializable transactions that have conflicts</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row255010377591"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1879711421804">FileStatLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p137976424018">Used to protect a data structure that stores statistics file information</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row8550163720595"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p147981942909">SyncRepLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p147988421607">Used to protect Xlog synchronization information during primary-standby replication</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1655020378590"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p177983421909">DataSyncRepLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p479816426013">Used to protect data page synchronization information during primary-standby replication</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row14551437115917"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8798144211010">CStoreColspaceCacheLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p16798442308">Used to add a lock when CU space is allocated for a column-store table</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1855103717598"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p2798184217010">CStoreCUCacheSweepLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p13799124220010">Used to add a lock when CU caches used by a column-store table are cyclically washed out</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row455183710597"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p07994425013">MetaCacheSweepLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p279914219018">Used to add a lock when metadata is cyclically washed out</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row11551193717598"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p177999421808">DfsConnectorCacheLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1079920423012">Used to protect a global hash table where HDFS connection handles are cached</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row114191650185911"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1799442902">dummyServerInfoCacheLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p780019420014">Used to protect a global hash table where the information about computing Node Group connections is cached</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row642035025915"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p280018421407">ExtensionConnectorLibLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1080017421606">Used to add a lock when a specific dynamic library is loaded or uninstalled in ODBC connection initialization scenarios</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1842045012596"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p148001542101">SearchServerLibLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p108001942206">Used to add a lock on the file read operation when a specific dynamic library is initially loaded in GPU-accelerated scenarios</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row4420150155910"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p580019422015">DfsUserLoginLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1800134213013">Used to protect a global linked table where HDFS user information is stored</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row15421195055911"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p108014423018">DfsSpaceCacheLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p480104212016">Used to ensure that the IDs of files to be imported to an HDFS table increase monotonically</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row0421105016597"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p680117423014">LsnXlogChkFileLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1480115421407">Used to serially update the Xlog flush points for primary and standby servers recorded in a specific structure</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row11421135015917"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p580116421404">GTMHostInfoLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p118017421304">Used to prevent concurrent access to or concurrent modification on GTM host information</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row04211750175913"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p680220429019">ReplicationSlotAllocationLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p38021042501">Used to add a lock when a primary server allocates stream replication slots during primary-standby replication</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row114227508594"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8802164218014">ReplicationSlotControlLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p58024428016">Used to prevent concurrent update of replication slot status during primary-standby replication</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row542255035919"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p580213428012">ResourcePoolHashLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p38021042806">Used to prevent concurrent access to or concurrent modification on a resource pool table, a hash table</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row20868166203"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p9803194211014">WorkloadStatHashLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1180313427012">Used to prevent concurrent access to or concurrent modification on a hash table that contains SQL requests from the CN side</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1086914615011"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p10803242807">WorkloadIoStatHashLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p38032426013">Used to prevent concurrent access to or concurrent modification on a hash table that contains the I/O information of the current DN</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row28691661019"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1280314213013">WorkloadCGroupHashLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p10803642307">Used to prevent concurrent access to or concurrent modification on a hash table that contains Cgroup information</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row08691561006"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p780414421604">OBSGetPathLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2804204216019">Used to prevent concurrent read/write or concurrent write/write on an OBS path</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row12870196705"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p168048423012">WorkloadUserInfoLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p780494210011">Used to prevent concurrent access to or concurrent modification on a hash table that contains user information about load management</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row48709611018"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p19804342808">WorkloadRecordLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p980412423016">Used to prevent concurrent access to or concurrent modification on a hash table that contains requests received by CNs during adaptive memory management</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row168707619014"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1580513427019">WorkloadIOUtilLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p0805042100">Used to protect a structure that records <strong id="EN-US_TOPIC_0000001233761803__b434816191918">iostat</strong> and CPU load information</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row6871961308"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p148059424012">WorkloadNodeGroupLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p880519421908">Used to prevent concurrent access to or concurrent modification on a hash table that contains Node Group information in memory</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row087146507"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p5805194216011">JobShmemLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p9805342907">Used to protect global variables in the shared memory that is periodically read during a scheduled task where MPP is compatible with Oracle</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row188728611010"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1180619421802">OBSRuntimeLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p8806742203">Used to obtain environment variables, for example, <em id="EN-US_TOPIC_0000001233761803__i1021820279342">GAUSSHOME</em>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1539715189019"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p9806184217015">LLVMDumpIRLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p48075423019">Used to export the assembly language for dynamically generating functions</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row839810181903"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p680784219018">LLVMParseIRLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p480717421603">Used to compile and parse a finished IR function from the IR file at the start position of a query</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row103986181309"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p7808124213014">RPNumberLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1180819423014">Used by a DN on a computing Node Group to count the number of threads for a task where plans are being executed</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1839810188016"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p7808194213010">ClusterRPLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p380824218013">Used to control concurrent access on cluster load data maintained in a CCN of the cluster</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row103985181306"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p18099421203">CriticalCacheBuildLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2080915426011">Used to load caches from a shared or local cache initialization file</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1739919182008"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p780974218018">WaitCountHashLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p980912421701">Used to protect a shared structure in user statement counting scenarios</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row143991818109"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p188091942900">BufMappingLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p128102042100">Used to protect operations on a table mapped to shared buffer</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row23991118102"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p081018421906">LockMgrLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1681016421108">It is used to protect a common lock structure.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row16400161816017"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p68105421506">PredicateLockMgrLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p17810144210016">Used to protect a lock structure that has serializable transactions</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1948295712012"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p11694903217">OperatorRealTLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2694120229">Used to prevent concurrent access to or concurrent modification on a global structure that contains real-time data at the operator level</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row7464418117"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p10694801823">OperatorHistLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p8695180420">Used to prevent concurrent access to or concurrent modification on a global structure that contains historical data at the operator level</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row18971267119"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1695701927">SessionRealTLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p166951909217">Used to prevent concurrent access to or concurrent modification on a global structure that contains real-time data at the query level</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row19996614"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p4695306217">SessionHistLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p96961708218">Used to prevent concurrent access to or concurrent modification on a global structure that contains historical data at the query level</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row8140714015"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1669612019211">CacheSlotMappingLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p126961708211">Used to protect global CU cache information</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1140614313"><td class="cellrowborder" valign="top" width="34.449999999999996%" headers="mcps1.3.7.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p3696901827">BarrierLock</p>
</td>
<td class="cellrowborder" valign="top" width="65.55%" headers="mcps1.3.7.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1697150128">Used to ensure that only one thread is creating a barrier at a time</p>
</td>
</tr>
</tbody>
</table>
</div>
<p id="EN-US_TOPIC_0000001233761803__p15563182016354">The following table describes the corresponding wait events when <strong id="EN-US_TOPIC_0000001233761803__b1546733124119">wait_status</strong> is <strong id="EN-US_TOPIC_0000001233761803__b55463308415">wait io</strong>.</p>
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001233761803__table674510341757" frame="border" border="1" rules="all"><caption><b>Table 4 </b>List of wait events corresponding to I/Os</caption><thead align="left"><tr id="EN-US_TOPIC_0000001233761803__row1974512342518"><th align="left" class="cellrowborder" valign="top" width="33.68%" id="mcps1.3.9.2.3.1.1"><p id="EN-US_TOPIC_0000001233761803__p10745334552">wait_event</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="66.32000000000001%" id="mcps1.3.9.2.3.1.2"><p id="EN-US_TOPIC_0000001233761803__p1974511341758">Description</p>
</th>
</tr>
</thead>
<tbody><tr id="EN-US_TOPIC_0000001233761803__row11745234456"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p7924553614">BufFileRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p19921155961">Reads data from a temporary file to a specified buffer.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1674520341757"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p3921551611">BufFileWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p139217551667">Writes the content of a specified buffer to a temporary file.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row47464343514"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p12921055564">ControlFileRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p18933552611">Reads the <strong id="EN-US_TOPIC_0000001233761803__b132821025132415">pg_control</strong> file, mainly during database startup, checkpoint execution, and primary/standby verification.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row774614344511"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p209313552068">ControlFileSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p9931855567">Flushes the <strong id="EN-US_TOPIC_0000001233761803__b4441452132814">pg_control</strong> file to a disk, mainly during database initialization.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row77469341159"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p10933551761">ControlFileSyncUpdate</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p99317551665">Flushes the <strong id="EN-US_TOPIC_0000001233761803__b12950158132912">pg_control</strong> file to a disk, mainly during database startup, checkpoint execution, and primary/standby verification.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row17461734957"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p209313551463">ControlFileWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1394655763">Writes to the <strong id="EN-US_TOPIC_0000001233761803__b74881331083">pg_control</strong> file, mainly during database initialization.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row674614341255"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p169410551866">ControlFileWriteUpdate</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p99410555610">Updates the <strong id="EN-US_TOPIC_0000001233761803__b597118201819">pg_control</strong> file, mainly during database startup, checkpoint execution, and primary/standby verification.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1991511238620"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p17941055663">CopyFileRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p89415551611">Reads a file during file copying.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row49163237610"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p19518556618">CopyFileWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p199510551610">Writes a file during file copying.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row59161123461"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p4951655269">DataFileExtend</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p795255363">Writes a file during file extension.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row11850629862"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p0962555619">DataFileFlush</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1696855265">Flushes a table data file to a disk.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row108511729761"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p7967551565">DataFileImmediateSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1696205517613">Flushes a table data file to a disk immediately.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row285113298613"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p89710551763">DataFilePrefetch</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p89717552616">Reads a table data file asynchronously.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1785110299614"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p797855064">DataFileRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p597755766">Reads a table data file synchronously.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1785218291767"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p10976559610">DataFileSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p99805519610">Flushes table data file modifications to a disk.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1385242915613"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p3988559619">DataFileTruncate</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p19981255366">Truncates a table data file.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row8853329867"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p12987551619">DataFileWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p18985558619">Writes a table data file.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row98539291562"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1899165515612">LockFileAddToDataDirRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1699105519611">Reads the <strong id="EN-US_TOPIC_0000001233761803__b5617185821113">postmaster.pid</strong> file.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row2853182912611"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p119913551060">LockFileAddToDataDirSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p79913555611">Flushes the <strong id="EN-US_TOPIC_0000001233761803__b1787338446">postmaster.pid</strong> file to a disk.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1485319291363"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p3995553613">LockFileAddToDataDirWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p31001855561">Writes the PID information into the <strong id="EN-US_TOPIC_0000001233761803__b055172917121">postmaster.pid</strong> file.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row49299371164"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p161001955065">LockFileCreateRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p141001555869">Read the LockFile file <strong id="EN-US_TOPIC_0000001233761803__b1449174417123">%s.lock</strong>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row2093003712611"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8100155511618">LockFileCreateSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p310112551363">Flushes the LockFile file <strong id="EN-US_TOPIC_0000001233761803__b660118211310">%s.lock</strong> to a disk.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row893015375610"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p910115551166">LockFileCreateWRITE</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p111011855863">Writes the PID information into the LockFile file <strong id="EN-US_TOPIC_0000001233761803__b1854193215132">%s.lock</strong>.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row09316378613"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p2101655166">RelationMapRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p410115551362">Reads the mapping file between system catalogs and storage locations.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row393114374618"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p11102145514612">RelationMapSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p91026553616">Flushes the mapping file between system catalogs and storage locations to a disk.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1093217371567"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8102185520617">RelationMapWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p2010220553616">Writes the mapping file between system catalogs and storage locations.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row493223716617"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p21031555769">ReplicationSlotRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1010319551568">Reads a stream replication slot file during a restart.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row5933537261"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p410320551666">ReplicationSlotRestoreSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p010320550613">Flushes a stream replication slot file to a disk during a restart.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1293313376618"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1610415554618">ReplicationSlotSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p4104855263">Flushes a temporary stream replication slot file to a disk during checkpoint execution.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row129333379613"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p110455510619">ReplicationSlotWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p3104055668">Writes a temporary stream replication slot file during checkpoint execution.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1293463714613"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p210515551461">SLRUFlushSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p101059551262">Flushes the <strong id="EN-US_TOPIC_0000001233761803__b1670618568207">pg_clog</strong>, <strong id="EN-US_TOPIC_0000001233761803__b142389593202">pg_subtrans</strong>, and <strong id="EN-US_TOPIC_0000001233761803__b187701416215">pg_multixact</strong> files to a disk, mainly during checkpoint execution and database shutdown.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row15934183716619"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p61057551166">SLRURead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p111053551616">Reads the <strong id="EN-US_TOPIC_0000001233761803__b1661318142113">pg_clog</strong>, <strong id="EN-US_TOPIC_0000001233761803__b204881720192117">pg_subtrans</strong>, and <strong id="EN-US_TOPIC_0000001233761803__b1389514222213">pg_multixact</strong> files.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row59342037062"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p910555516610">SLRUSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p41067551618">Writes dirty pages into the <strong id="EN-US_TOPIC_0000001233761803__b1199163219219">pg_clog</strong>, <strong id="EN-US_TOPIC_0000001233761803__b7474153512212">pg_subtrans</strong>, and <strong id="EN-US_TOPIC_0000001233761803__b106934409216">pg_multixact</strong> files, and flushes the files to a disk, mainly during checkpoint execution and database shutdown.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row17935143711615"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8106125510620">SLRUWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p81068550619">Writes the <strong id="EN-US_TOPIC_0000001233761803__b186311393229">pg_clog</strong>, <strong id="EN-US_TOPIC_0000001233761803__b1566361122211">pg_subtrans</strong>, and <strong id="EN-US_TOPIC_0000001233761803__b127881013102213">pg_multixact</strong> files.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row4935133713618"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p12106185513612">TimelineHistoryRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p010616551618">Reads the timeline history file during database startup.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row193515376615"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p201076557611">TimelineHistorySync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p7107125514613">Flushes the timeline history file to a disk during database startup.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row109353372069"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p510718556619">TimelineHistoryWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p01071355069">Writes to the timeline history file during database startup.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row8936153716614"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p175089521070">TwophaseFileRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p11508205215718">Reads the <strong id="EN-US_TOPIC_0000001233761803__b192893620231">pg_twophase</strong> file, mainly during two-phase transaction submission and restoration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row8663991579"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p8508105217710">TwophaseFileSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p5508952276">Flushes the <strong id="EN-US_TOPIC_0000001233761803__b4506948142317">pg_twophase</strong> file to a disk, mainly during two-phase transaction submission and restoration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row3280111319720"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p125092525715">TwophaseFileWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p16509115215717">Writes the <strong id="EN-US_TOPIC_0000001233761803__b15647855142311">pg_twophase</strong> file, mainly during two-phase transaction submission and restoration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row92818131979"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p350916527718">WALBootstrapSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1250985212713">Flushes an initialized WAL file to a disk during database initialization.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row345581715717"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p11510352578">WALBootstrapWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p18510752676">Writes an initialized WAL file during database initialization.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1145515176712"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p135101652775">WALCopyRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1351075211717">Read operation generated when an existing WAL file is read for replication after archiving and restoration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row144561179713"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p145105521475">WALCopySync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p20511352177">Flushes a replicated WAL file to a disk after archiving and restoration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row245661712715"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p18511155217717">WALCopyWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p5511205217715">Write operation generated when an existing WAL file is read for replication after archiving and restoration.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row487822113718"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1051245212712">WALInitSync</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1512145218716">Flushes a newly initialized WAL file to a disk during log reclaiming or writing.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row15878921678"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p35124521279">WALInitWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1251211521378">Initializes a newly created WAL file to 0 during log reclaiming or writing.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1087811213710"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p95134521078">WALRead</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p5513185219718">Reads data from Xlogs during redo operations on two-phase files.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row787962119713"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p151425218711">WALSyncMethodAssign</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1651416521377">Flushes all open WAL files to a disk.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row9879162120715"><td class="cellrowborder" valign="top" width="33.68%" headers="mcps1.3.9.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p125141252978">WALWrite</p>
</td>
<td class="cellrowborder" valign="top" width="66.32000000000001%" headers="mcps1.3.9.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1651411521872">Writes a WAL file.</p>
</td>
</tr>
</tbody>
</table>
</div>
<p id="EN-US_TOPIC_0000001233761803__p17382359163616">The following table describes the corresponding wait events when <strong id="EN-US_TOPIC_0000001233761803__b1380431693217">wait_status</strong> is <strong id="EN-US_TOPIC_0000001233761803__b1616182513214">acquire lock</strong>.</p>
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001233761803__table9718135411310" frame="border" border="1" rules="all"><caption><b>Table 5 </b>List of wait events corresponding to transaction locks</caption><thead align="left"><tr id="EN-US_TOPIC_0000001233761803__row8719115417315"><th align="left" class="cellrowborder" valign="top" width="32.65%" id="mcps1.3.11.2.3.1.1"><p id="EN-US_TOPIC_0000001233761803__p673513253413">wait_event</p>
</th>
<th align="left" class="cellrowborder" valign="top" width="67.35%" id="mcps1.3.11.2.3.1.2"><p id="EN-US_TOPIC_0000001233761803__p1571995411319">Description</p>
</th>
</tr>
</thead>
<tbody><tr id="EN-US_TOPIC_0000001233761803__row5719205412317"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p206511937848">relation</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p465216370413">Adds a lock to a table.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row107199547314"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p206521237745">extend</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p106521037942">Adds a lock to a table being scaled out.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row4720105418313"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p965223711413">partition</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p965213377416">Adds a lock to a partitioned table.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row197209541832"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p1265218372043">partition_seq</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p26533376414">Adds a lock to a partition of a partitioned table.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row10720175417311"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p86538375412">page</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p106533372043">Adds a lock to a table page.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row107205541232"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p96531737447">tuple</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p4654183718417">Adds a lock to a tuple on a page.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row5721754733"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p665418371646">transactionid</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p11654143717416">Adds a lock to a transaction ID.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row143181015744"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p86542371848">virtualxid</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p16543371946">Adds a lock to a virtual transaction ID.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row2318315542"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p06557372041">object</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p19655837845">Adds a lock to an object.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1231816154416"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p136557372041">cstore_freespace</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p1565516371643">Adds a lock to idle column-store space.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row1631916151748"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p15655173711419">userlock</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p116556371941">Adds a lock to a user.</p>
</td>
</tr>
<tr id="EN-US_TOPIC_0000001233761803__row73191815745"><td class="cellrowborder" valign="top" width="32.65%" headers="mcps1.3.11.2.3.1.1 "><p id="EN-US_TOPIC_0000001233761803__p206566371949">advisory</p>
</td>
<td class="cellrowborder" valign="top" width="67.35%" headers="mcps1.3.11.2.3.1.2 "><p id="EN-US_TOPIC_0000001233761803__p96561337043">Adds an advisory lock.</p>
</td>
</tr>
</tbody>
</table>
</div>
</div>
<div>
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