On Thu, 2010-09-23 at 16:18 +0300, Heikki Linnakangas wrote:
> There's a program called pg_readahead somewhere on pgfoundry by NTT that
> will help if it's the single-threadedness of I/O. Before handing the WAL
> file to the server, it scans it through and calls posix_fadvise for all
> the blocks that it touches. When the server then replays it, the data
> blocks are already being fetched by the OS, using the whole RAID array.
That sounds useful, thanks for the hint !
But couldn't this also be directly built in to WAL recovery process ? It
would probably help a lot for recovering from a crash too. We did have
recently a crash and it took hours to recover.
I will try it out as soon as I get the time to set it up...
[searching pgfoundry]
Unfortunately I can't find it, and google is also not very helpful. Do
you happen to have some links to it ?
Cheers,
Csaba.