Re: logical decoding : exceeded maxAllocatedDescs for .spill files - Mailing list pgsql-hackers

From Andres Freund
Subject Re: logical decoding : exceeded maxAllocatedDescs for .spill files
Date
Msg-id 20200218060353.kf3fp2dbl3vv6gjr@alap3.anarazel.de
Whole thread Raw
In response to Re: logical decoding : exceeded maxAllocatedDescs for .spill files  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: logical decoding : exceeded maxAllocatedDescs for .spill files  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
On 2020-02-18 11:20:17 +0530, Amit Kapila wrote:
> Andres, any objections on proceeding with Kuntal's patch for
> back-branches (10, 9.6 and 9.5)?

Yes. In my past experiments that lead to *terrible* allocator
performance due to fragmentation. Like, up to 90% of the time spent in
aset.c.  Try a workload with a number of overlapping transactions that
have different tuple sizes.

I'm not even sure it's the right thing to do anything in the back
branches to be honest. If somebody hits this badly they likely have done
so before, and they at least have the choice to upgrade, but if we
regress performance for more people...



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