Horton

Re: Out of Memory errors are frustrating as heck!

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@2ndquadrant.com>
Cc: Andres Freund <andres@anarazel.de>, Gunther <raj@gusw.net>, Jeff Janes <jeff.janes@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, pgsql-performance@lists.postgresql.org, Justin Pryzby <pryzby@telsasoft.com>
Date: 2019-04-15T17:45:00Z
Lists: pgsql-performance 
Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> Seems that ExecHashJoinGetSavedTuple stores a minimalTuple and sets the
> shouldFree flag to "true", and then in ExecHashJoinNewBatch, callee
> ExecFetchSlotMinimalTuple sets shouldFree to false inconditionally when
> the slot uses minimal tuple ops.  Maybe that's correct, but it does
> sound like a memory leak is not entirely impossible.  I wonder if this
> fixes it, without causing crashes elsewhere.

This discussion is about v11, not HEAD.  Still, I agree that that
coding in HEAD seems a bit fishy.

			regards, tom lane

Commits

  1. Consider BufFiles when adjusting hashjoin parameters

  2. Allocate hash join files in a separate memory context