Re: Proposing pg_hibernate

Le lundi 3 février 2014 19:18:54 Gurjeet Singh a écrit :
> Possible enhancements:
> - Ability to save/restore only specific databases.
> - Control how many BlockReaders are active at a time; to avoid I/O
> storms. - Be smart about lowered shared_buffers across the restart.
> - Different modes of reading like pg_prewarm does.
> - Include PgFincore functionality, at least for Linux platforms.

Please note that pgfincore is working on any system where PostgreSQL
prefetch is working, exactly like pg_prewarm. This includes linux, BSD and
many unix-like. It *is not* limited to linux.
I never had a single request for windows, but windows does provides an
API for that too (however I have no windows offhand to test).

Another side note is that currently BSD (at least freeBSD) have a more
advanced mincore() syscall than linux and offers a better analysis (dirty
status is known) and they implemented posix_fadvise...

PS:
There is a previous thread about that hibernation feature. Mitsuru IWASAKI
did a patch, and it triggers some interesting discussions.
Some notes in this thread are outdated now, but it's worth having a look
at it:

http://www.postgresql.org/message-id/20110504.231048.113741617.iwasaki@jp.FreeBSD.org

https://commitfest.postgresql.org/action/patch_view?id=549

--
Cédric Villemain +33 (0)6 20 30 22 52
http://2ndQuadrant.fr/
PostgreSQL: Support 24x7 - Développement, Expertise et Formation