Repeated PredicateLockRelation calls during seqscan

From: Dan Ports <drkp(at)csail(dot)mit(dot)edu>
To: pgsql-hackers(at)postgresql(dot)org, Kevin Grittner <Kevin(dot)Grittner(at)wicourts(dot)gov>
Subject: Repeated PredicateLockRelation calls during seqscan
Date: 2011-06-22 04:58:50
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I was looking at ExecSeqScan today and noticed that it invokes
PredicateLockRelation each time it's called, i.e. for each tuple
returned. Any reason we shouldn't skip that call if
rs_relpredicatelocked is already set, as in the attached patch?

That would save us a bit of overhead, since checking that flag is
cheaper than doing a hash lookup in the local predicate lock table
before bailing out.


Dan R. K. Ports MIT CSAIL

Attachment Content-Type Size
predlock-seqscan.patch text/x-diff 824 bytes


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