On 11/17/15 4:41 AM, Thom Brown wrote:
Could someone post a TL;DR summary of what the current plan looks like? I can see there is a huge amount of discussion to trawl back through. I can see it's something to do with the visibility map. And does it avoid freezing very large tables like the title originally sought?
Basically, it follows the same pattern that all-visible bits do, except instead of indicating a page is all-visible, the bit shows that all tuples on the page are frozen. That allows a scan_all vacuum to skip those pages.
-- Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX Experts in Analytics, Data Architecture and PostgreSQL Data in Trouble? Get it in Treble! http://BlueTreble.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers