From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | greigwise <greigwise(at)comcast(dot)net> |
Cc: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: BitmapAnd on correlated column? |
Date: | 2019-10-04 13:35:05 |
Message-ID: | 4678.1570196105@sss.pgh.pa.us |
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Lists: | pgsql-general |
greigwise <greigwise(at)comcast(dot)net> writes:
> Granted it cannot skip the condition, but that doesn't mean that it has to
> use that second index. It's doing a recheck on the conditions anyway,
> right?
I'm afraid you're out of luck on that for now. In principle, the
presence of extended stats on the column combination might allow
the planner to figure out that the second IN condition adds little
selectivity. But I'm not sure how hard it would be, and I am sure
that the extended-stats logic hasn't been built out in that direction
yet.
regards, tom lane
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