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@ -251,12 +251,13 @@ ANALYZE [ VERBOSE ] [ <replaceable class="parameter">table_and_columns</replacea |
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</para> |
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<para> |
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If the table being analyzed has one or more children, |
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<command>ANALYZE</command> will gather statistics twice: once on the |
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rows of the parent table only, and a second time on the rows of the |
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parent table with all of its children. This second set of statistics |
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is needed when planning queries that traverse the entire inheritance |
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tree. The autovacuum daemon, however, will only consider inserts or |
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If the table being analyzed has inheritance children, |
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<command>ANALYZE</command> gathers two sets of statistics: one on the rows |
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of the parent table only, and a second including rows of both the parent |
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table and all of its children. This second set of statistics is needed when |
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planning queries that process the inheritance tree as a whole. The child |
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tables themselves are not individually analyzed in this case. |
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The autovacuum daemon, however, will only consider inserts or |
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updates on the parent table itself when deciding whether to trigger an |
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automatic analyze for that table. If that table is rarely inserted into |
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or updated, the inheritance statistics will not be up to date unless you |
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@ -272,15 +273,6 @@ ANALYZE [ VERBOSE ] [ <replaceable class="parameter">table_and_columns</replacea |
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partitioning it's guaranteed to be empty. |
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</para> |
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<para> |
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By contrast, if the table being analyzed has inheritance children, |
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<command>ANALYZE</command> gathers two sets of statistics: one on the rows |
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of the parent table only, and a second including rows of both the parent |
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table and all of its children. This second set of statistics is needed when |
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planning queries that process the inheritance tree as a whole. The child |
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tables themselves are not individually analyzed in this case. |
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</para> |
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<para> |
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The autovacuum daemon does not process partitioned tables, nor does it |
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process inheritance parents if only the children are ever modified. |
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