Re: Polyphase merge is obsolete - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: Polyphase merge is obsolete
Date
Msg-id 91284957-3cb2-944e-5f14-5c2ff86b49fa@iki.fi
Whole thread Raw
In response to Re: Polyphase merge is obsolete  (vignesh C <vignesh21@gmail.com>)
Responses Re: Polyphase merge is obsolete  (Jaime Casanova <jcasanov@systemguards.com.ec>)
List pgsql-hackers
On 14/07/2021 15:12, vignesh C wrote:
> On Sat, Jan 23, 2021 at 3:49 AM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
>> Here's an updated version that fixes one bug:
>>
>> The CFBot was reporting a failure on the FreeBSD system [1]. It turned
>> out to be an out-of-memory issue caused by an underflow bug in the
>> calculation of the size of the tape read buffer size. With a small
>> work_mem size, the memory left for tape buffers was negative, and that
>> wrapped around to a very large number. I believe that was not caught by
>> the other systems, because the other ones had enough memory for the
>> incorrectly-sized buffers anyway. That was the case on my laptop at
>> least. It did cause a big slowdown in the 'tuplesort' regression test
>> though, which I hadn't noticed.
>>
>> The fix for that bug is here as a separate patch for easier review, but
>> I'll squash it before committing.
> 
> The patch does not apply on Head anymore, could you rebase and post a
> patch. I'm changing the status to "Waiting for Author".

Here's a rebased version. I also squashed that little bug fix from 
previous patch set.

- Heikki

Attachment

pgsql-hackers by date:

Previous
From: Mark Dilger
Date:
Subject: Re: Extending amcheck to check toast size and compression
Next
From: Tomas Vondra
Date:
Subject: Re: row filtering for logical replication