| From: | Jim Nasby <Jim(dot)Nasby(at)BlueTreble(dot)com> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com> |
| Cc: | Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: optimizing vacuum truncation scans |
| Date: | 2015-07-27 22:32:53 |
| Message-ID: | 55B6B195.9090601@BlueTreble.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 7/27/15 10:39 AM, Robert Haas wrote:
> But that's not enough: we also need to know that any tuple that
> survived the prune operation (that is, it wasn't redirected or marked
> unused) has a new-enough xmin, which isn't tracked anywhere.
Wouldn't that be old-enough xmin?
heap_prune_chain() is already calling HeapTupleSatisfiesVacuum, so it
should be able to figure out if the page is all visible without a lot of
extra work, and pass that info back to heap_page_prune (which would then
pass it down to _execute()).
Definitely not a one-liner though.
--
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Data in Trouble? Get it in Treble! http://BlueTreble.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Josh Berkus | 2015-07-27 22:56:03 | Re: Autonomous Transaction is back |
| Previous Message | Joel Jacobson | 2015-07-27 22:12:43 | Re: Autonomous Transaction is back |