Re: Plan time Improvement - 64bit bitmapset - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Plan time Improvement - 64bit bitmapset
Date
Msg-id 25009.1244063503@sss.pgh.pa.us
Whole thread Raw
In response to Re: Plan time Improvement - 64bit bitmapset  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Plan time Improvement - 64bit bitmapset
List pgsql-hackers
"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> Since he can't share the schema, and hasn't even given much of a hint,
> I don't know whether one (or more) of the columns is a bytea filled
> with 100 MB values; and I don't remember any description of the
> hardware environment either.  Since the behavior seems so
> out-of-the-ordinary, I was casting about for possible extraordinary
> characteristics of his environment which might cause it.  I'm probably
> way off base....

There's a hard-wired restriction in analyze.c that makes it discard data
values wider than 1KB on-sight.  So no such value will ever be found in
a statistics array.  You could still have a few meg in a pg_statistics
row, I suppose, but not a really horrendous amount.
        regards, tom lane


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