Jan Wieck wrote:
> Bruce Momjian wrote:
>
> > Now, O_SYNC is going to force every write to the disk. If we have a
> > transaction that has to write lots of buffers (has to write them to
> > reuse the shared buffer)
>
> So make the background writer/checkpointer keeping the LRU head clean. I
> explained that 3 times now.
If the background cleaner has to not just write() but write/fsync or
write/O_SYNC, it isn't going to be able to clean them fast enough. It
creates a bottleneck where we didn't have one before.
We are trying to eliminate an I/O storm during checkpoint, but the
solutions seem to be making the non-checkpoint times slower.
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
359-1001+ If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square,
Pennsylvania19073
