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Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com> Co-authored-by: luhuayi <luhuayi@huawei.com> Co-committed-by: luhuayi <luhuayi@huawei.com>
163 lines
20 KiB
HTML
163 lines
20 KiB
HTML
<a name="EN-US_TOPIC_0000001764650100"></a><a name="EN-US_TOPIC_0000001764650100"></a>
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<h1 class="topictitle1">PG_INDEX</h1>
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<div id="body8662426"><p id="EN-US_TOPIC_0000001764650100__a91dff33929754cad9ed1ec7ff55563f5"><strong id="EN-US_TOPIC_0000001764650100__b215523110101">PG_INDEX</strong> records part of the information about indexes. The rest is mostly in <strong id="EN-US_TOPIC_0000001764650100__b62014777181338">PG_CLASS</strong>.</p>
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<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" id="EN-US_TOPIC_0000001764650100__td4e4a89935514fe38b527c4d54042d41" frame="border" border="1" rules="all"><caption><b>Table 1 </b>PG_INDEX columns</caption><thead align="left"><tr id="EN-US_TOPIC_0000001764650100__r16a742e12bad4fd49bcea852383b9c79"><th align="left" class="cellrowborder" valign="top" width="25.77%" id="mcps1.3.2.2.4.1.1"><p id="EN-US_TOPIC_0000001764650100__aa3037774b7924c438f2fc400681eb024"><strong id="EN-US_TOPIC_0000001764650100__b137159395843432">Column</strong></p>
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</th>
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<th align="left" class="cellrowborder" valign="top" width="16.73%" id="mcps1.3.2.2.4.1.2"><p id="EN-US_TOPIC_0000001764650100__a1fb7aa0b90fb4b5a9058d1809c02b303">Type</p>
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</th>
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<th align="left" class="cellrowborder" valign="top" width="57.49999999999999%" id="mcps1.3.2.2.4.1.3"><p id="EN-US_TOPIC_0000001764650100__a1e1852c14095403097929d32779f6037">Description</p>
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</th>
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</tr>
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</thead>
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<tbody><tr id="EN-US_TOPIC_0000001764650100__rea8a971d46134a6e8f00faa9c43e7272"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__acb82e7f5b95140da93a4bab35adba8bd">indexrelid</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__af69e07bdb6ec493c8ac8619499b9752c">OID</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a6ccfedba1b554efbbced5b1566fec36a">OID of the <strong id="EN-US_TOPIC_0000001764650100__b173931241163116">pg_class</strong> entry for this index</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__rfc6f91789ffe49b09f4e686d3368c71c"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a1a73304a624442cdbca2e04dbd5af1ae">indrelid</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a48ebd626f50a499aacfe44abaa6e44b2">OID</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__ad1515d7ba8ed4a7a9326431edb6948ed">OID of the <strong id="EN-US_TOPIC_0000001764650100__b15927125193114">pg_class</strong> entry for the table this index is for</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__rbcdd8eec0935449f942d1bc1f37537e8"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a36a25b84aac7424e9a4a589497e2b466">indnatts</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a6a55f851cfff45dba45c0767924e0c12">Smallint</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a1f13190e702a4184a43e2c5c0d3762a8">Number of columns in an index</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r698e9f241d8c45eaa4496c39e337e327"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a10d2ae990d074e8abf4f5bf21b73f3f8">indisunique</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__ac4a8edc6e7154a4180060c7af3d30a1f"><span id="EN-US_TOPIC_0000001764650100__text116873515365">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a5d981ef856194d86967233a8f3c5a2d4">This index is a unique index if the value is <strong id="EN-US_TOPIC_0000001764650100__b172451043191618">true</strong>.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r1c969b6b94a444e9b3854ca20752b319"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a72a322ae611644cda63100eae746eede">indisprimary</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__aebec782e735848c0a967db39035dc8d1"><span id="EN-US_TOPIC_0000001764650100__text27764615369">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a9694486607684a44a61637c692ba3e27">This index represents the primary key of the table if the value is <strong id="EN-US_TOPIC_0000001764650100__b1985662531611">true</strong>. If this value is <strong id="EN-US_TOPIC_0000001764650100__b14869568348">true</strong>, the value of <strong id="EN-US_TOPIC_0000001764650100__b58085160349">indisunique</strong> is true.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r81fef77c3c934160af1614c17d7a1d44"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a377b1afb346941f5b18b40b3e5f9545d">indisexclusion</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a53ca9991422a47d890262ff00c83650d"><span id="EN-US_TOPIC_0000001764650100__text3764127163615">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a92bbd6aceed847908bb16afd1144a737">This index supports exclusion constraints if the value is <strong id="EN-US_TOPIC_0000001764650100__b84462902411049">true</strong>.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r2e7e929cfadf47d59910627c77bcd78c"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a231825cc985c420bac6d11a6bd97316a">indimmediate</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a8d857669fe9b464c874d1d5c38f1caaa"><span id="EN-US_TOPIC_0000001764650100__text96471893616">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a6d2d16c6b29c4e38a4998168974b990e">A uniqueness check is performed upon data insertion if the value is <strong id="EN-US_TOPIC_0000001764650100__b23832061716">true</strong>.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__ree02bfe606e34ea7bdb67189a016a3ee"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__ad08c0f4772ef42c89d7ea12cf7e7e43f">indisclustered</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a2f0da046958c4c2b89351315186a8a86"><span id="EN-US_TOPIC_0000001764650100__text2589149153612">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a54cc2eb89a1049a8823095498d6cf762">The table was last clustered on this index if the value is <strong id="EN-US_TOPIC_0000001764650100__b1036117540350">true</strong>.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r53fccb749c7f4f7e95b48365ea1ddd1c"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__aefe5c97c8d7540b9aa8a3310fe3fb36c">indisusable</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a44edf2ec3d2642809326e43ec4c7bd9a"><span id="EN-US_TOPIC_0000001764650100__text113382010163612">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a6b687344038c471ea5473009c648e3f6">This index supports insert/select if the value is <strong id="EN-US_TOPIC_0000001764650100__b15381183461715">true</strong>.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r9cf4f21bc90e46efbd9342d00dea2d1b"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__ac81210a187c04c0a9d7f87f707516cdc">indisvalid</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__ad28135cc08ee4ffc90a529738530d3b5"><span id="EN-US_TOPIC_0000001764650100__text12184611173616">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a9345cb871ce24e348537d178c0e19cad">This index is valid for queries if the value is <strong id="EN-US_TOPIC_0000001764650100__b135004091917">true</strong>. If this column is <strong id="EN-US_TOPIC_0000001764650100__b84235270620740">false</strong>, this index is possibly incomplete and must still be modified by <strong id="EN-US_TOPIC_0000001764650100__b17555161111220">INSERT/UPDATE</strong> operations, but it cannot safely be used for queries. If it is a unique index, the uniqueness property is also not true.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r0f969166ccd346b89b671b3550d5e258"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a24b992c64681441b8925da09ec04d61d">indcheckxmin</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__af1d738a3b35c4855a85a1bbba462be64"><span id="EN-US_TOPIC_0000001764650100__text116218129364">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a85f56eaa3d14495bbe111d7809c4ebab">If the value is <strong id="EN-US_TOPIC_0000001764650100__b842352706114022">true</strong>, queries must not use the index until the xmin of this row in <strong id="EN-US_TOPIC_0000001764650100__b842352706113946">pg_index</strong> is below their <strong id="EN-US_TOPIC_0000001764650100__b84235270611402">TransactionXmin</strong> event horizon, because the table may contain broken HOT chains with incompatible rows that they can see.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r6f9701466e6b49a3ba93a660c976c65c"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__acf2919910675439aa1e49e2b8f462d35">indisready</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__ac4002560aa834c1e82f55575a856b9b2"><span id="EN-US_TOPIC_0000001764650100__text12903171353611">boolean</span></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a4802e05354a9455bb1772932be618499">If the value is <strong id="EN-US_TOPIC_0000001764650100__b20101113110517">true</strong>, this index is ready for inserts. If the value is <strong id="EN-US_TOPIC_0000001764650100__b56995152570">false</strong>, this index is ignored when data is inserted or modified.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r4c86b37e87704d3a8ed8c92538e81da9"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a29cd09f4bee3468cbc7d63176d675297">indkey</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a39167292a36c4fb08fdfd029c27c035c">int2vector</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a55fa6bc596c24943bafa353a8584f561">This is an array of <strong id="EN-US_TOPIC_0000001764650100__b4218395577">indnatts</strong> values that indicate which table columns this index creates. For example, a value of <strong id="EN-US_TOPIC_0000001764650100__b343534019594">1 3</strong> means that the first and the third columns make up the index key. <strong id="EN-US_TOPIC_0000001764650100__b84235270620752">0</strong> in this array indicates that the corresponding index attribute is an expression over the table columns, rather than a simple column reference.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r9a70417de898491a8af2527a0a3c37b4"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a5969f6dfebfd40e6a9bd8babef548e4d">indcollation</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__abf568806ecbc4dd393f7bc61072f4f07">oidvector</p>
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<p id="EN-US_TOPIC_0000001764650100__aa6dbbd7663cd412c81e2a31fbf844b6c"></p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a0722071b1003490ba379b4b86e2899eb">ID of each column used by the index</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__rc53e6c9335a44e4d8626f353dc8e333d"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a9b37c4734e70412c90789ad18d9da5de">indclass</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a46203e7aea7e40dc8eeafd907c98934d">oidvector</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__ac3e60b650f2842889788c476f5638032">For each column in the index key, this column contains the OID of the operator class to use. For details, see <a href="dws_04_0603.html">PG_OPCLASS</a>.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r6d5490867ef14065b1ea4c071f335007"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__af2a48fdc45d94f3fbe8c47c97173c566">indoption</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__adb29e26a60a8445ebe157dc210f65e8e">int2vector</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__af57d6e0b43df42a68cfb6787cdf87858">Array of values that store per-column flag bits. The meaning of the bits is defined by the index's access method.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__r9147b076789e4ff0843e7d31dd6e06be"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__ad71d1b15d75844f7b10e7f0e2c18e1a6">indexprs</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__add9adc8f90f64939aa90ebdeba09321c">pg_node_tree</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a8dbd928961834812aa88743c7bfb216e">Expression trees (in <strong id="EN-US_TOPIC_0000001764650100__b67945308811049">nodeToString()</strong> representation) for index attributes that are not simple column references. It is a list with one element for each zero entry in <strong id="EN-US_TOPIC_0000001764650100__b115409475111049">INDKEY</strong>. NULL if all index attributes are simple references.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__rd49cf2a509444850b3adc9a38dae4db5"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__a6500caa59d9142cbb3687b5d5a61d6e3">indpred</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__a9b6148dd368b400180d86f28adb10cd4">pg_node_tree</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__a0d6b80aba0f54ea1857e6eccacd840fd">Expression tree (in <strong id="EN-US_TOPIC_0000001764650100__b144403498118">nodeToString()</strong> representation) for partial index predicate. If the index is not a partial index, the value is null.</p>
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</td>
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</tr>
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<tr id="EN-US_TOPIC_0000001764650100__row94651335163114"><td class="cellrowborder" valign="top" width="25.77%" headers="mcps1.3.2.2.4.1.1 "><p id="EN-US_TOPIC_0000001764650100__p9465103517314">indnullstreatment</p>
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</td>
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<td class="cellrowborder" valign="top" width="16.73%" headers="mcps1.3.2.2.4.1.2 "><p id="EN-US_TOPIC_0000001764650100__p6466935113117">tinyint</p>
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</td>
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<td class="cellrowborder" valign="top" width="57.49999999999999%" headers="mcps1.3.2.2.4.1.3 "><p id="EN-US_TOPIC_0000001764650100__p9592151871710">Processing mode of the <strong id="EN-US_TOPIC_0000001764650100__b13741920113219">NULL</strong> value in the unique index. This field is valid only if <strong id="EN-US_TOPIC_0000001764650100__b1780293018320">indisunique</strong> is set to <strong id="EN-US_TOPIC_0000001764650100__b966714319323">true</strong>.</p>
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<p id="EN-US_TOPIC_0000001764650100__p12914191617019">Options:</p>
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<ul id="EN-US_TOPIC_0000001764650100__ul1971164321613"><li id="EN-US_TOPIC_0000001764650100__li20976152311188"><strong id="EN-US_TOPIC_0000001764650100__b4307173813494">0</strong>: <strong id="EN-US_TOPIC_0000001764650100__b118334064916">NULLS DISTINCT</strong>. <strong id="EN-US_TOPIC_0000001764650100__b10634192110509">NULL</strong> values are not equivalent and can be inserted repeatedly.</li><li id="EN-US_TOPIC_0000001764650100__li1545145591618"><strong id="EN-US_TOPIC_0000001764650100__b13959132665113">1</strong>: <strong id="EN-US_TOPIC_0000001764650100__b7135122995120">NULLS NOT DISTINCT</strong>. <strong id="EN-US_TOPIC_0000001764650100__b1439552610533">NULL</strong> values are equivalent and cannot be inserted repeatedly.</li><li id="EN-US_TOPIC_0000001764650100__li1071194351619"><strong id="EN-US_TOPIC_0000001764650100__b8620162113523">2</strong>: <strong id="EN-US_TOPIC_0000001764650100__b623892315527">NULLS IGNORE</strong>. <strong id="EN-US_TOPIC_0000001764650100__b1533161810548">NULL</strong> columns are ignored during equivalent comparison. If all index columns are <strong id="EN-US_TOPIC_0000001764650100__b4937114625412">NULL</strong>, <strong id="EN-US_TOPIC_0000001764650100__b03315013545">NULL</strong> values can be inserted repeatedly. If part of the index columns are <strong id="EN-US_TOPIC_0000001764650100__b1011311179555">NULL</strong>, data can be inserted only if non-null values are different.</li></ul>
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<p id="EN-US_TOPIC_0000001764650100__p356913519115">Default value: <strong id="EN-US_TOPIC_0000001764650100__b685543015556">0</strong></p>
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<div class="note" id="EN-US_TOPIC_0000001764650100__note10761172916719"><span class="notetitle"> NOTE: </span><div class="notebody"><ul id="EN-US_TOPIC_0000001764650100__ul159063464418"><li id="EN-US_TOPIC_0000001764650100__li164061033184410">If the current cluster was upgraded from an earlier version to 8.2.0.100, the value of this field is <strong id="EN-US_TOPIC_0000001764650100__b43741711466">NULL</strong> for existing indexes. For newly created indexes, the value of this field is determined by the <strong id="EN-US_TOPIC_0000001764650100__b149681221369">[ NULLS [NOT] DISTINCT | NULLS IGNORE ]</strong> field. The default value is <strong id="EN-US_TOPIC_0000001764650100__b114113131815">0</strong>.</li><li id="EN-US_TOPIC_0000001764650100__li99071041448">If the current cluster is newly installed and its version is 8.2.0.100, for newly created indexes, the value of this field is determined by the <strong id="EN-US_TOPIC_0000001764650100__b7935181019817">[ NULLS [NOT] DISTINCT | NULLS IGNORE ]</strong> field. The default value is <strong id="EN-US_TOPIC_0000001764650100__b8569123411614">0</strong>.</li></ul>
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</div></div>
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</td>
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</tr>
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</tbody>
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</table>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_04_0561.html">System Catalogs</a></div>
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</div>
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</div>
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