Re: Faster CREATE DATABASE by delaying fsync (was 8.4.1 ubuntu karmic slow createdb)

On Mon, Jan 18, 2010 at 4:35 PM, Greg Stark <gsstark@mit.edu> wrote:
> Looking at this patch for the commitfest I have a few questions.

So I've touched this patch up a bit:

1) moved the posix_fadvise call to a new fd.c function
pg_fsync_start(fd,offset,nbytes) which initiates an fsync without
waiting on it. Currently it's only implemented with
posix_fadvise(DONT_NEED) but I want to look into using sync_file_range
in the future -- it looks like this call might be good enough for our
checkpoints.

2) advised each 64k chunk as we write it which should avoid poisoning
the cache if you do a large create database on an active system.

3) added the promised but afaict missing fsync of the directory -- i
think we should actually backpatch this.

Barring any objections shall I commit it like this?


-- 
greg


-- 
greg