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