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Re: SQL Challenge: Arbitrary Cross-tab

From: "Greg Sabino Mullane" <greg(at)turnstep(dot)com>
To: pgsql-sql(at)postgresql(dot)org
Subject: Re: SQL Challenge: Arbitrary Cross-tab
Date: 2004-08-20 02:16:50
Message-ID: a1aa78544af9cfda7c505876591e95dc@biglumber.com (view raw or flat)
Thread:
Lists: pgsql-sql
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> Nope; Gaetano's right, you cannot assume that.  It's entirely possible
> for the planner to choose different plans depending on the OFFSET.
> (Maybe not very likely, with such small offsets, but could happen.)
 
Interesting. I realized that there was a finite chance of different
plans being chosen, but it seemed neigh-impossible since there is
no WHERE clause and the offsets only vary from 0-7. What sort of
different plans would it choose, out of curiosity?
Seq-scan vs. index-scan? Are there any particular cases where the
same plan is guaranteed to be used?
 
- --
Greg Sabino Mullane greg(at)turnstep(dot)com
PGP Key: 0x14964AC8 200408192216
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Subject: Re: SQL Challenge: Arbitrary Cross-tab
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