| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> |
| Cc: | Matthew Wakeling <matthew(at)flymine(dot)org>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: merge join killing performance |
| Date: | 2010-05-20 14:28:12 |
| Message-ID: | 3829.1274365692@sss.pgh.pa.us |
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| Lists: | pgsql-hackers pgsql-performance |
Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com> writes:
> So, Tom, so you think it's possible that the planner isn't noticing
> all those nulls and thinks it'll just take a row or two to get to the
> value it needs to join on?
Could be. I don't have time right now to chase through the code, but
that sounds like a plausible theory.
regards, tom lane
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