"Qingqing Zhou" <zhouqq(at)cs(dot)toronto(dot)edu> writes:
> This is a patch for write performance, but here theoretically decreases the
> read performance due to the possible setting of XLOG_BLCKSZ (say 512 as
> sector size, which is << BLCKSZ). It maybe avoidable by still using BLCKSZ
> or even more aggresive block size, but may also need some local tweak here.
(1) I really don't think we care that much about read performance on xlog.
(2) Buffering should be the kernel's problem, not ours. Since we don't
specify O_DIRECT during reading, the kernel ought to be perfectly
capable of recognizing the opportunity for read-ahead on these fetches.
regards, tom lane