On 11 October 2012 01:43, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I think we have to revert and go back to the drawing board on this.
Given that change was also sold on the basis of higher performance, I
suggest we retest performance to check there is a gain. If there is
still a gain, I suggest we add this as a SIGHUP option, default to
off, rather than completely remove it.
I might also observe since the problem only happens with lock waits,
perhaps we can set a flag can_reuse_snapshot that gets cleared if we
need to perform a lock wait before executing the main statement.
-- Simon Riggs http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services
