Re: Excessive WAL generation and related performance issue

Joe Conway <mail@joeconway.com> writes:
> In other words, based on my inserted logic, it appears that there are
> 5 and 6 backup blocks on a fairly regular basis.

> However in xlog.h it says:
> 8<--------------------------
>  * If we backed up any disk blocks with the XLOG record, we use flag
>  * bits in xl_info to signal it.  We support backup of up to 4 disk
>  * blocks per XLOG record.
> 8<--------------------------

> So is my logic to record number of backup blocks wrong, or is the
> comment wrong, or am I otherwise misunderstanding something?

The comment is correct, so you did something wrong.  From memory,
there's a goto-label retry loop in that function; maybe you need
to zero your counters after the retry label?
        regards, tom lane