po 26. 4. 2021 v 19:10 odesÃlatel Tom Lane <t...@sss.pgh.pa.us> napsal:
> Pavel Stehule <pavel.steh...@gmail.com> writes:
> > I tried to write a query that does lateral join between
> > information_schema.tables and pgstattuple function.
>
> > select * from information_schema.tables, lateral(select * from
> > pgstattuple(table_name::name)) s where table_type = 'BASE TABLE';
>
> > The query finished by strange error
>
> > postgres=# select * from information_schema.tables, lateral(select * from
> > pgstattuple(table_name::name)) s where table_type = 'BASE TABLE';
> > ERROR: relation "sql_features" does not exist
>
> > When I set search_path to information_schema, then the query is running.
> > But there is not any reason why it should be necessary.
>
> Nope, this is classic user error, nothing else. "table_name::name"
> is entirely inadequate as a way to reference a table that isn't
> visible in your search path. You have to incorporate the schema
> name as well.
>
> Ideally you'd just pass the table OID to the OID-accepting version of
> pgstattuple(), but of course the information_schema schema views
> don't expose OIDs. So basically you need something like
>
>
> pgstattuple((quote_ident(table_schema)||'.'||quote_ident(table_name))::regclass)
>
> although perhaps format() could help a little here.
>
I understand now. Thank you for explanation
select * from information_schema.tables, lateral(select * from
pgstattuple(format('%I.%I', table_schema, table_name))) s where table_type
= 'BASE TABLE';
This is working
Regards
Pavel
>
> regards, tom lane
>
