Hello
I found SELECT pg_stat_statements_reset(NULL,NULL,s.queryid) in tests and it pass tests, but i wonder how it works. Should not we check the NULL through PG_ARGISNULL macro before any PG_GETARG_*? According src/include/fmgr.h
> * If function is not marked "proisstrict" in pg_proc, it must check for
> * null arguments using this macro. Do not try to GETARG a null argument!
> pg_stat_statements_reset(userid Oid, dbid Oid, queryid bigint) returns void
And you forgot to change return type in docs (and description of return value)
regards, Sergei