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doc-exports/docs/dws/dev/dws_06_0150.html
Lu, Huayi a24ca60074 DWS DEVELOPER 811 version 
Reviewed-by: Hasko, Vladimir <vladimir.hasko@t-systems.com>
Co-authored-by: Lu, Huayi <luhuayi@huawei.com>
Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
2023-01-19 13:37:49 +00:00

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<a name="EN-US_TOPIC_0000001145510681"></a><a name="EN-US_TOPIC_0000001145510681"></a>
<h1 class="topictitle1">ALTER VIEW</h1>
<div id="body8662426"><div class="section" id="EN-US_TOPIC_0000001145510681__se300da7053554cb58cc5988526228ed0"><h4 class="sectiontitle">Function</h4><p id="EN-US_TOPIC_0000001145510681__ace403db5736840f08d3e8a83b362a1a0"><strong id="EN-US_TOPIC_0000001145510681__b842352706135951">ALTER VIEW</strong> modifies all auxiliary attributes of a view. (To modify the query definition of a view, use <strong id="EN-US_TOPIC_0000001145510681__b842352706155656">CREATE OR REPLACE VIEW</strong>.)</p>
</div>
<div class="section" id="EN-US_TOPIC_0000001145510681__s9264977dc26a4c7f8993cc31dd59c965"><h4 class="sectiontitle">Precautions</h4><ul id="EN-US_TOPIC_0000001145510681__u376c43d0bff54635af4347cf838af540"><li id="EN-US_TOPIC_0000001145510681__lea26b84d3a20447db1aacf011618c25d">Only the view owner can modify a view by running <strong id="EN-US_TOPIC_0000001145510681__en-us_topic_0058965798_b84235270615579">ALTER VIEW</strong>.</li><li id="EN-US_TOPIC_0000001145510681__l5d7f4089a82e4f418d4f3b3ad6c7e998">To change a view's schema, you must also have the CREATE permission on the new schema.</li><li id="EN-US_TOPIC_0000001145510681__la53e1fdd278f4f25ab112424aef64dc8">To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have CREATE privilege on the view's schema.</li><li id="EN-US_TOPIC_0000001145510681__lf37c72c968cb4a3ba5447daab11d3f76">An administrator can change the owner relationship of any view.</li></ul>
</div>
<div class="section" id="EN-US_TOPIC_0000001145510681__sba7861b1289b443a9ce4f3f5c63c3b75"><h4 class="sectiontitle">Syntax</h4><ul id="EN-US_TOPIC_0000001145510681__u63e03f7051194d6b9b24114f6bfd0e47"><li id="EN-US_TOPIC_0000001145510681__l7019d52a46aa40e1b3a31c5d9df0e5f6">Set the default value of the view column.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__sa5e6878264054aee81e7ef940725639c"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"></span>
<span class="w"> </span><span class="k">ALTER</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">COLUMN</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="k">column_name</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="k">DEFAULT</span><span class="w"> </span><span class="n">expression</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__l902ad79032f1473387936d1fce0d5dcf">Remove the default value of the view column.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__sdff0b53455b348eeb414529c6a2fd172"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"></span>
<span class="w"> </span><span class="k">ALTER</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">COLUMN</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="k">column_name</span><span class="w"> </span><span class="k">DROP</span><span class="w"> </span><span class="k">DEFAULT</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__l2328b9a023324c99b1527d5a98fbc657">Change the owner of a view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__s5c5a8f5ff1464915bb8672748b9f2289"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"> </span>
<span class="w"> </span><span class="k">OWNER</span><span class="w"> </span><span class="k">TO</span><span class="w"> </span><span class="n">new_owner</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__l22abade4313c4daf83f3e4f761ce0fbd">Rename a view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__s7eba3cc08b8b418286729d633112367b"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"> </span>
<span class="w"> </span><span class="k">RENAME</span><span class="w"> </span><span class="k">TO</span><span class="w"> </span><span class="n">new_name</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__lc1ad4a77c809441fa995be048343b24c">Set the schema of the view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__sc1e494c759e149868dde3be30d0b2e96"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"> </span>
<span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="k">SCHEMA</span><span class="w"> </span><span class="n">new_schema</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__l35e2c862bd6f426686cba91eb7324adb">Set the options of the view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__s6745f3816a6a434ea8253cf3939cd6ef"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"></span>
<span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="p">(</span><span class="w"> </span><span class="err">{</span><span class="w"> </span><span class="n">view_option_name</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">view_option_value</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="err">}</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="p">);</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__lf51008b52ec54903997cad12be86635c">Reset the options of the view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__scc594fee6e074b1a99231105402a4018"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"></span>
<span class="w"> </span><span class="k">RESET</span><span class="w"> </span><span class="p">(</span><span class="w"> </span><span class="n">view_option_name</span><span class="w"> </span><span class="p">[,</span><span class="w"> </span><span class="p">...</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="p">);</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li></ul>
</div>
<ul id="EN-US_TOPIC_0000001145510681__ul44958391768"><li id="EN-US_TOPIC_0000001145510681__li118528441862">Rebuild a view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__screen15852104416617"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"></span>
<span class="w"> </span><span class="n">REBUILD</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li></ul>
<ul id="EN-US_TOPIC_0000001145510681__ul174377201539"><li id="EN-US_TOPIC_0000001145510681__li1437192045311">Rebuild a dependent view.<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__screen24371420115317"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span>
<span class="normal">2</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="k">ONLY</span><span class="w"> </span><span class="p">[</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="k">EXISTS</span><span class="w"> </span><span class="p">]</span><span class="w"> </span><span class="n">view_name</span><span class="w"></span>
<span class="w"> </span><span class="n">REBUILD</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</li></ul>
<div class="section" id="EN-US_TOPIC_0000001145510681__s4dd504151fa34b0cb75ad8ff975e1d7f"><h4 class="sectiontitle">Parameter Description</h4><ul id="EN-US_TOPIC_0000001145510681__uce6e8b3a80854100ac72c9f9f04f6a45"><li id="EN-US_TOPIC_0000001145510681__l2abbccbb1277427ab75b18aee67429ea"><strong id="EN-US_TOPIC_0000001145510681__abbd8dacdd87a403da70037dcc0bbea62">IF EXISTS</strong><p id="EN-US_TOPIC_0000001145510681__af765f2d8d70d404781eb6a372b28a75f">If this option is specified, no error is reported if the view does not exist. Only a message is displayed.</p>
</li><li id="EN-US_TOPIC_0000001145510681__l0871fc3385d54be98452e84435aafc75"><strong id="EN-US_TOPIC_0000001145510681__a90d56c413f8444f7a6e45ce17ff68542">view_name</strong><p id="EN-US_TOPIC_0000001145510681__afa6218e04cc94a2895b3509333098086">Specifies the view name, which can be schema-qualified.</p>
<p id="EN-US_TOPIC_0000001145510681__a8d8ceee9db584d5199c9755947a557dd">Value range: a string. It must comply with the naming convention.</p>
</li><li id="EN-US_TOPIC_0000001145510681__lbba72815a2724c6498dafa4bcd22d783"><strong id="EN-US_TOPIC_0000001145510681__a436d8b474b6d4f1287d7d1587f97b49c">column_name</strong><p id="EN-US_TOPIC_0000001145510681__a122fdcf973bd44529167c04a00df1182">Indicates an optional list of names to be used for columns of the view. If not given, the column names are deduced from the query.</p>
<p id="EN-US_TOPIC_0000001145510681__a80fc1590e09140f4a4d876f94a851010">Value range: a string. It must comply with the naming convention.</p>
</li><li id="EN-US_TOPIC_0000001145510681__lf77bedac8fc34adb99354d7630054531"><strong id="EN-US_TOPIC_0000001145510681__a315851eaadb54e6aa426c47b5c09c0e4">SET/DROP DEFAULT</strong><p id="EN-US_TOPIC_0000001145510681__a678b7fe67b1c4cbca9f73f97d3d93b99">Sets or deletes the default value of a column. Currently, this parameter does not take effect.</p>
</li><li id="EN-US_TOPIC_0000001145510681__l3eb8abf1d8294654a04e38315314a074"><strong id="EN-US_TOPIC_0000001145510681__a84f174c78574490897108924376f07e4">new_owner</strong><p id="EN-US_TOPIC_0000001145510681__a8ae31462851343808c6fbb253b2d485e">Specifies the new owner of a view.</p>
</li><li id="EN-US_TOPIC_0000001145510681__l802fd9fadd614d468574f699b75ba825"><strong id="EN-US_TOPIC_0000001145510681__a298348d8ef084dd3bbe59eee56637fc7">new_name</strong><p id="EN-US_TOPIC_0000001145510681__a83a4e8fde85742b2868c2721e5ae6d22">Specifies the new view name.</p>
</li><li id="EN-US_TOPIC_0000001145510681__lee078c0324d64a56851f9d653dbdf9a3"><strong id="EN-US_TOPIC_0000001145510681__a4ae281ceb8fd4ba5bcc69e8a76990e5b">new_schema</strong><p id="EN-US_TOPIC_0000001145510681__a7a57caf650c0496c97008e3ec00008b1">Specifies the new schema of the view.</p>
</li><li id="EN-US_TOPIC_0000001145510681__l1b3c3a1d30024252af23e6622a44cf0e"><strong id="EN-US_TOPIC_0000001145510681__ae77fb773f36e46779f43ed6d31de5f99">view_option_name [ = view_option_value ]</strong><p id="EN-US_TOPIC_0000001145510681__a6a972606a8f84d00b96200534c211842">This clause specifies optional parameters for a view.</p>
<p id="EN-US_TOPIC_0000001145510681__a736afe4deeee4d1ea95294505e8e681d">Currently, the only parameter supported by <strong id="EN-US_TOPIC_0000001145510681__b842352706113540">view_option_name</strong> is <strong id="EN-US_TOPIC_0000001145510681__b109079317316">security_barrier</strong>, which should be enabled when a view is intended to provide row-level security.</p>
<p id="EN-US_TOPIC_0000001145510681__aee1b8198b3a04ee38ad1416c8ac743b8">Value range: <span id="EN-US_TOPIC_0000001145510681__text1199152416173">boolean</span> type. It can be <strong id="EN-US_TOPIC_0000001145510681__b2443531181712">TRUE</strong> or <strong id="EN-US_TOPIC_0000001145510681__b1878743381717">FALSE</strong>.</p>
</li><li id="EN-US_TOPIC_0000001145510681__li1849814457175"><strong id="EN-US_TOPIC_0000001145510681__b17834115111175">REBUILD</strong><div class="p" id="EN-US_TOPIC_0000001145510681__p749817457176">This clause is used for view decoupling. You can use the saved original statement to rebuild views and restore the dependencies. Note the following:<ul id="EN-US_TOPIC_0000001145510681__ul5126172716577"><li id="EN-US_TOPIC_0000001145510681__li1612662735710">View rebuilding starts from the current view and updates all associated backward views. If the forward views on which the current view depends are also unavailable, automatic rebuilding is triggered.</li><li id="EN-US_TOPIC_0000001145510681__li770763611572">The temporary tables and views that have dependency relationships cannot be decoupled and dropped. However, you can perform the REBUILD operation on temporary views that do not have dependency relationships.</li><li id="EN-US_TOPIC_0000001145510681__li357745745717">View schema names and view names can be modified. The names of rebuilt view schemas or views are re-created based on the latest name, but the query operation retains the original definition.</li><li id="EN-US_TOPIC_0000001145510681__li329183016319">Only fields of the character, number, and time types in the base table can be modified.</li><li id="EN-US_TOPIC_0000001145510681__li187074318319">Invalid views are exported as comments during backup. You need to manually restore the invalid views.</li><li id="EN-US_TOPIC_0000001145510681__li78611610182419">Views can be automatically rebuilt when <strong id="EN-US_TOPIC_0000001145510681__b1084134214310">VIEW_INDEPENDENT</strong> is set to <strong id="EN-US_TOPIC_0000001145510681__b241183013912">on</strong>.</li></ul>
</div>
</li><li id="EN-US_TOPIC_0000001145510681__li139991826414">ONLY<p id="EN-US_TOPIC_0000001145510681__p52313233416"><a name="EN-US_TOPIC_0000001145510681__li139991826414"></a><a name="li139991826414"></a>Only views and their dependent views are rebuilt. This function is available only if <strong id="EN-US_TOPIC_0000001145510681__b1122663317419">view_independent</strong> is set to <strong id="EN-US_TOPIC_0000001145510681__b12232233444">on</strong>.</p>
</li></ul>
</div>
<div class="section" id="EN-US_TOPIC_0000001145510681__s7d7b3396e68c4011b95c1e02a254a932"><h4 class="sectiontitle">Examples</h4><p id="EN-US_TOPIC_0000001145510681__p98246385220">Rename a view.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__screen113541339155319"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="n">tpcds</span><span class="p">.</span><span class="n">customer_details_view_v1</span><span class="w"> </span><span class="k">RENAME</span><span class="w"> </span><span class="k">TO</span><span class="w"> </span><span class="n">customer_details_view_v2</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001145510681__p128241531525">Change the schema of a view.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__screen422915116540"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="n">tpcds</span><span class="p">.</span><span class="n">customer_details_view_v2</span><span class="w"> </span><span class="k">SET</span><span class="w"> </span><span class="k">schema</span><span class="w"> </span><span class="k">public</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001145510681__p9824336522">Rebuild a view.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__screen52426291727"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="k">public</span><span class="p">.</span><span class="n">customer_details_view_v2</span><span class="w"> </span><span class="n">REBUILD</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
<p id="EN-US_TOPIC_0000001145510681__p198241433520">Rebuild a dependent view.</p>
<div class="codecoloring" codetype="Sql" id="EN-US_TOPIC_0000001145510681__screen22315228212"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal">1</span></pre></div></td><td class="code"><div><pre><span></span><span class="k">ALTER</span><span class="w"> </span><span class="k">VIEW</span><span class="w"> </span><span class="k">ONLY</span><span class="w"> </span><span class="k">public</span><span class="p">.</span><span class="n">customer_details_view_v2</span><span class="w"> </span><span class="n">REBUILD</span><span class="p">;</span><span class="w"></span>
</pre></div></td></tr></table></div>
</div>
</div>
<div class="section" id="EN-US_TOPIC_0000001145510681__s727775a9b4004b4dbef41d0d3a428719"><h4 class="sectiontitle">Helpful Links</h4><p id="EN-US_TOPIC_0000001145510681__a88a3942f38cc47dbb84fd5eeefe6c115"><a href="dws_06_0187.html">CREATE VIEW</a>, <a href="dws_06_0215.html">DROP VIEW</a></p>
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<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_06_0118.html">DDL Syntax</a></div>
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