Horton

Re: [PATCH] XLogReadRecord returns pointer to currently read page

Andrei Lepikhov <a.lepikhov@postgrespro.ru>

View thread View on postgr.es
From: Andrey Lepikhov <a.lepikhov@postgrespro.ru>
To: Heikki Linnakangas <hlinnaka@iki.fi>, PostgreSQL-Dev <pgsql-hackers@postgresql.org>
Date: 2018-10-23T05:25:27Z
Lists: pgsql-hackers

Attachments

On 23.10.2018 0:53, Heikki Linnakangas wrote:
> I'd expect the decompression to read from the on-disk buffer, and unpack 
> to readRecordBuf, I still don't see a need to copy the packed record to 
> readRecordBuf. If there is a need for that, though, the patch that 
> implements the packing or compression can add the memcpy() where it 
> needs it.

I agree with it. Eventually, placement of the WAL-record can be defined 
by comparison the record, readBuf and readRecordBuf pointers.
In attachment new version of the patch.

-- 
Andrey Lepikhov
Postgres Professional
https://postgrespro.com
The Russian Postgres Company

Commits

  1. Improve description of buffer used to store records in WAL reader

  2. Remove unnecessary memcpy when reading WAL record fitting on page