pgstattuple: Have pgstattuple_approx accept TOAST tables

On Fri, 2020-04-17 at 13:01 +0200, Peter Eisentraut wrote:

I alluded to this in [0], but it's better discussed in its own thread.

I think the check that makes pgstattuple_approx reject TOAST tables is a
mistake. They have visibility and free space map, and it works just
fine if the check is removed.

Attached is a patch to fix this and add some tests related to how
pgstattuple and pg_visibility accept TOAST tables for inspection.

[0]:
/messages/by-id/dc35a398-37d0-75ce-07ea-1dd71d98f8ec@2ndquadrant.com

I gave the patch a spin, and it passes regression tests and didn't
cause any problems when I played with it.

No upgrade or dump considerations, of course.

This is a clear improvement.

I'll mark the patch as "ready for committer".

Yours,
Laurenz Albe

On 2020-06-17 13:39, Laurenz Albe wrote:

On Fri, 2020-04-17 at 13:01 +0200, Peter Eisentraut wrote:

I alluded to this in [0], but it's better discussed in its own thread.

I think the check that makes pgstattuple_approx reject TOAST tables is a
mistake. They have visibility and free space map, and it works just
fine if the check is removed.

Attached is a patch to fix this and add some tests related to how
pgstattuple and pg_visibility accept TOAST tables for inspection.

[0]:
/messages/by-id/dc35a398-37d0-75ce-07ea-1dd71d98f8ec@2ndquadrant.com

I gave the patch a spin, and it passes regression tests and didn't
cause any problems when I played with it.

No upgrade or dump considerations, of course.

This is a clear improvement.

I'll mark the patch as "ready for committer".

committed, thanks

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