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create_misc.sql

  • Tom Lane's avatar
    e40f3c74
    ANALYZE a_star and its children to avoid plan instability in tests. · e40f3c74
    Tom Lane authored
    We've noted certain EXPLAIN queries on these tables occasionally showing
    unexpected plan choices.  This seems to happen because VACUUM sometimes
    fails to update relpages/reltuples for one of these single-page tables,
    due to bgwriter or checkpointer holding a pin on the lone page at just
    the wrong time.  To ensure those values get set, insert explicit ANALYZE
    operations on these tables after we finish populating them.  This
    doesn't seem to affect any other test cases, so it's a usable fix.
    
    Back-patch to v12.  In principle the issue exists further back, but
    we have not seen it before v12, so I won't risk back-patching further.
    
    Discussion: https://postgr.es/m/24480.1569518042@sss.pgh.pa.us
    e40f3c74
    History
    ANALYZE a_star and its children to avoid plan instability in tests.
    Tom Lane authored
    We've noted certain EXPLAIN queries on these tables occasionally showing
    unexpected plan choices.  This seems to happen because VACUUM sometimes
    fails to update relpages/reltuples for one of these single-page tables,
    due to bgwriter or checkpointer holding a pin on the lone page at just
    the wrong time.  To ensure those values get set, insert explicit ANALYZE
    operations on these tables after we finish populating them.  This
    doesn't seem to affect any other test cases, so it's a usable fix.
    
    Back-patch to v12.  In principle the issue exists further back, but
    we have not seen it before v12, so I won't risk back-patching further.
    
    Discussion: https://postgr.es/m/24480.1569518042@sss.pgh.pa.us