> The "delete" took about 2 seconds. I then did it over with the
> 'value' being a 5K chunk of text, which according to octet_length
> got compressed to 3900 bytes. (This'd require two rows in the TOAST
> table.) This time the delete took 127 seconds. I was expecting
> about a 3X penalty since we needed to delete three rows not one,
> but what I got was a 60X penalty.
Wow. Can someone remind me why we take page images on delete? We
aren't really writing anything special to the page except a transction
id.
> I've worried for some time that the decision to XLOG page images was
> costing us a lot more performance than could be justified...
Is it because we take a snapshot of the page before we write it in case
we only write part of the page?
-- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610)
853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill,
Pennsylvania19026
