Hi Pavan,
On 3/14/19 2:20 PM, Masahiko Sawada wrote:
On Thu, Mar 14, 2019 at 5:17 PM Pavan Deolasee <pavan.deola...@gmail.com> wrote:
Ok. I will run some tests. But please note that this patch is a bug fix to
address the performance issue that is caused by having to rewrite the entire
table when all-visible bit is set on the page during first vacuum. So while we
may do some more work during COPY FREEZE, we're saving a lot of page writes
during next vacuum. Also, since the scan that we are doing in this patch is
done on a page that should be in the buffer cache, we will pay a bit in terms
of CPU cost, but not anything in terms of IO cost.
Agreed. I had been misunderstanding this patch. The page scan during
COPY FREEZE is necessary and it's very cheaper than doing in the first
vacuum.
I have removed Ibrar as a reviewer since there has been no review from
them in three weeks, and too encourage others to have a look.
Regards,
--
-David
da...@pgmasters.net
