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: Gunther <raj@gusw.net>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Justin Pryzby <pryzby@telsasoft.com>, Jeff Janes <jeff.janes@gmail.com>, pgsql-performance@lists.postgresql.org, Alvaro Herrera <alvherre@2ndquadrant.com>
Date: 2019-08-23T14:20:31Z
Lists: pgsql-performance 
Gunther <raj@gusw.net> writes:
> Hi all, I am connecting to a discussion back from April this year. My 
> data has grown and now I am running into new out of memory situations. 

It doesn't look like this has much of anything to do with the hash-table
discussion.  The big hog is an ExprContext:

> ExprContext: 1107296256 total in 142 blocks; 6328 free (101 chunks); 
> 1107289928 used

So there's something leaking in there, but this isn't enough info
to guess what.

			regards, tom lane

Commits

  1. Consider BufFiles when adjusting hashjoin parameters

  2. Allocate hash join files in a separate memory context