Re: pgsql: Define a separately configurable XLOG_BLCKSZ symbol for the page

"Qingqing Zhou" <zhouqq@cs.toronto.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