Re: Configuring BLCKSZ and XLOGSEGSZ (in 8.3)

"Simon Riggs" <simon@2ndquadrant.com> writes:
> On Mon, 2006-11-27 at 18:26 -0500, Tom Lane wrote:
>> [ studies code a bit more... ]  I'm also wondering whether the forced
>> pg_control update at each xlog seg switch is worth its keep.  Offhand
>> it seems like the checkpoint pointer is enough; why are we maintaining
>> logId/logSeg in pg_control?

> We maintain the values in shared memory to allow us to determine whether
> or not its time to checkpoint, and also to ensure that there is one and
> only one call to checkpoint. So we need to keep track of this somewhere
> and that may as well be where it already is.

Say again?  AFAICT those fields are write-only; the only place we
consult them is to decide whether they need to be updated.  My thought
was to remove 'em altogether.

            regards, tom lane