On 4 August 2016 at 05:57, Masahiko Sawada <sawada.m...@gmail.com> wrote:
> While reviewing freeze map code, Andres pointed out[1] that > lazy_scan_heap could accesses visibility map twice and its logic is > seems a bit tricky. > As discussed before, it's not nice especially when large relation is > entirely frozen. > > I posted the patch for that before but since this is an optimization, > not bug fix, I'd like to propose it again. > Please give me feedback. > > [1] > https://www.postgresql.org/message-id/20160505000840.epatoq6d2e556446%40alap3.anarazel.de If we have a freeze map now, surely tables will no longer be entirely frozen? What performance difference does this make, in a realistic use case? How would we test this to check it is exactly correct? -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
