Andre Schubert <andre(at)km3(dot)de> writes:
> Ok, but is there another way to enable STATS_ROW_LEVEL for a special
> backend not connecting as superuser ?
No: the code is deliberately designed to prevent that, on the grounds
that it'd be a security flaw (non-superusers should not be allowed to
hide their activities from the DBA).
There's nothing to stop you from making a private version with
stats_row_level downgraded to an ordinary unprotected SET variable,
though, if that seems more appropriate to your needs. See its entry in
src/backend/utils/misc/guc.c and change it from SUSET to USERSET
category (from memory; check spelling in src/include/utils/guc.h).
regards, tom lane