Re: pgstattuple_approx for toasted table

Mariel Cherkassky wrote:
> I was testing pgstattuple and I realized that pgstattuple is working on toasted table but pgstattuple_approx is raising the next error msg :
>
> ERROR: "pg_toast_18292" is not a table or materialized view
>
> ahm, is that because the pgstattuple_approx uses visibility map ? Can someone explain ? tnx.

You are right; here is the code:

/*
* We support only ordinary relations and materialised views, because we
* depend on the visibility map and free space map for our estimates about
* unscanned pages.
*/
if (!(rel->rd_rel->relkind == RELKIND_RELATION ||
rel->rd_rel->relkind == RELKIND_MATVIEW))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("\"%s\" is not a table or materialized view",
RelationGetRelationName(rel))));

Yours,
Laurenz Albe

--
Cybertec | https://www.cybertec-postgresql.com