Re: hyrax vs. RelationBuildPartitionDesc - Mailing list pgsql-hackers

From Robert Haas
Subject Re: hyrax vs. RelationBuildPartitionDesc
Date
Msg-id CA+TgmoZjwB2kRvDz56PWDjApy5Jkt5SEywwYUn9uSQP2hAd+Ww@mail.gmail.com
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In response to Re: hyrax vs. RelationBuildPartitionDesc  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: hyrax vs. RelationBuildPartitionDesc
List pgsql-hackers
On Fri, May 17, 2019 at 4:36 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Yeah, I did some additional testing that showed that it's pretty darn
> hard to get the leak to amount to anything.  The test case that I
> originally posted did many DDLs in a single transaction, and it
> seems that that's actually essential to get a meaningful leak; as
> soon as you exit the transaction the leaked contexts will be recovered
> during sinval cleanup.

My colleague Amul Sul rediscovered this same leak when he tried to
attach lots of partitions to an existing partitioned table, all in the
course of a single transaction.  This seems a little less artificial
than Tom's original reproducer, which involved attaching and detaching
the same partition repeatedly.

Here is a patch that tries to fix this, along the lines I previously
suggested; Amul reports that it does work for him.  I am OK to hold
this for v13 if that's what people want, but I think it might be
smarter to commit it to v12.  Maybe it's not a big leak, but it seems
easy enough to do better, so I think we should.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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