BUG #16670: pgstattuple ERROR: relation "sql_implementation_info" does not exist
The following bug has been logged on the website:
Bug reference: 16670
Logged by: Marc Rechté
Email address: mrechte@gmail.com
PostgreSQL version: 13.0
Operating system: CentOS8
Description:
Hello,
I get an error with pgstattuple extension.
On PG13.0:
# select tablename,
(pgstattuple_approx(tablename::regclass)).approx_free_space from pg_tables
where schemaname = 'public' and
(pgstattuple_approx(tablename::regclass)).approx_free_percent > 10;
ERROR: relation "sql_implementation_info" does not exist
On PG12.3:
# select tablename,
(pgstattuple_approx(tablename::regclass)).approx_free_space from pg_tables
where schemaname = 'public' and
(pgstattuple_approx(tablename::regclass)).approx_free_percent > 10;
ERROR: relation "sql_packages" does not exist
Note that the where clause on approx_free_percent is the error cause.
Thanks
PG Bug reporting form <noreply@postgresql.org> writes:
# select tablename,
(pgstattuple_approx(tablename::regclass)).approx_free_space from pg_tables
where schemaname = 'public' and
(pgstattuple_approx(tablename::regclass)).approx_free_percent > 10;
ERROR: relation "sql_implementation_info" does not exist
This is not a bug. We don't guarantee anything about the evaluation
order of WHERE clauses. Even if we did, this query has got bugs of
its own: it will fail on tablenames that would require quoting,
such as names containing spaces, dots, uppercase letters, etc.
You could write
(quote_ident(schemaname)||'.'||quote_ident(tablename))::regclass
to avoid both of those issues. There are still going to be some race
condition problems around just-dropped tables, though.
regards, tom lane