Horton

Re: Need Multixact Freezing Docs

Alvaro Herrera <alvherre@2ndquadrant.com>

View thread View on postgr.es
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-hackers@postgresql.org
Date: 2015-06-14T14:50:18Z
Lists: pgsql-hackers

Attachments

Josh Berkus wrote:
> 
> > You can see the current multixact value in pg_controldata output.  Keep
> > timestamped values of that somewhere (a table?) so that you can measure
> > consumption rate.  I don't think we provide SQL-level access to those
> > values.
> 
> Bleh.  Do we provide SQL-level access in 9.4?  If not, I think that's a
> requirement before release.  Telling users to monitor a setting using a
> restricted-permission command-line utility which produces a
> version-specific text file they have to parse is not going to win us a
> lot of fans.

I found that I had written a very quick accessor function to multixact
shared state data awhile ago.  This might be useful for monitoring
purposes.  What do people think of including this for 9.5?  It needs a
small change to add the newly added oldestOffset (plus a little cleanup
and docs).

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Document pg_get_multixact_members().