On 2016-01-07 11:27:13 +0100, Fabien COELHO wrote:
> I read your patch and I know what I want to try to have a small and simple
> fix. I must admit that I have not really understood in which condition the
> checkpointer would decide to close a file, but that does not mean that the
> potential issue should not be addressed.
There's a trivial example: Consider three tablespaces and
max_files_per_process = 2. The balancing can easily cause three files
being flushed at the same time.
But more importantly: You designed the API to be generic because you
wanted it to be usable for other purposes as well. And for that it
certainly needs to deal with that.
> Also, I gave some thoughts about what should be done for bgwriter random
> IOs. The idea is to implement some per-file sorting there and then do some
> LRU/LFU combing. It would not interact much with the checkpointer, so for me
> the two issues should be kept separate and this should not preclude changing
> the checkpointer, esp. given the significant performance benefit of the
Well, the problem is that the patch significantly regresses some cases
right now. So keeping them separate isn't particularly feasible.
Sent via pgsql-hackers mailing list (firstname.lastname@example.org)
To make changes to your subscription: