Re: Use get_call_result_type() more widely

On Wed, Dec 14, 2022 at 11:14:59AM +0530, Bharath Rupireddy wrote:
> AFAICS, most of these functions have no direct source code callers,
> they're user-facing functions and not in a hot code path. I measured
> the test times of these functions and I don't see much difference [1].

Thanks for the summary.  It looks like your tests involve single
runs.  What is the difference in run-time when invoking this
repeatedly with a large generate_series() for example when few or no
tuples are returned?  Do you see a difference in perf profile?  Some
of the functions could have their time mostly eaten while looking at
the syscache on repeated calls, but you could see the actual work this
involves with a dummy function that returns a large number of
attributes on a single record in the worst case possible?

Separating things into two buckets..

> [1]
> pg_old_snapshot_time_mapping() - an extension function with no
> internal source code callers, no test coverage.
> pg_visibility_map_summary() - an extension function with no internal
> source code callers, test coverage exists, test times on HEAD:25 ms
> PATCHED:25 ms
> pg_last_committed_xact() and pg_xact_commit_timestamp_origin() - no
> internal source code callers, test coverage exists, test times on
> HEAD:10 ms PATCHED:10 ms> pg_get_multixact_members() - no internal source code callers, no test coverage.
> pg_control_recovery() and pg_control_init() - test coverage exists,
> test times on HEAD:42 ms PATCHED:44 ms
> pg_identify_object() - no internal source code callers, test coverage
> exists, test times on HEAD:17 ms PATCHED:18 ms
> pg_identify_object_as_address() - no internal source code callers,
> test coverage exists, test times on HEAD:66 ms PATCHED:60 ms
> pg_get_object_address() - no internal source code callers, test
> coverage exists, test times on HEAD:66 ms PATCHED:60 ms
> pg_sequence_parameters() - no internal source code callers, test
> coverage exists, test times on HEAD:96 ms PATCHED:98 ms
> ts_token_type_byid(), ts_token_type_byname(), ts_parse_byid() and
> ts_parse_byname() - internal source code callers exists, test coverage
> exists, test times on HEAD:195 ms, pg_dump 10 wallclock secs
> PATCHED:186 ms, pg_dump 10 wallclock secs
> pg_get_keywords() - no internal source code callers, test coverage
> exists, test times on HEAD:129 ms PATCHED:130 ms
> pg_get_catalog_foreign_keys() - no internal source code callers, test
> coverage exists, test times on HEAD:114 ms PATCHED:111 ms
> tsvector_unnest() - no internal source code callers, test coverage
> exists, test times on HEAD:26 ms PATCHED:26 ms
> ts_setup_firstcall() - test coverage exists, test times on HEAD:195 ms
> PATCHED:186 ms
> pg_partition_tree() - no internal source code callers, test coverage
> exists, test times on HEAD:30 ms PATCHED:32 ms
> pg_timezone_abbrevs() - no internal source code callers, test coverage
> exists, test times on HEAD:40 ms PATCHED:36 ms

These ones don't worry me much, TBH.

> pg_stat_get_wal(), pg_stat_get_archiver() and
> pg_stat_get_replication_slot() - no internal source code callers, test
> coverage exists, test times on HEAD:479 ms PATCHED:483 ms
> pg_prepared_xact() - no internal source code callers, test coverage
> exists, test times on HEAD:50 ms, subscription 108 wallclock secs,
> recovery 111 wallclock secs PATCHED:48 ms, subscription 110 wallclock
> secs, recovery 112 wallclock secs
> show_all_settings(), pg_control_system(), pg_control_checkpoint(),
> test_predtest() - no internal source code callers, test coverage
> exists, test times on HEAD:18 ms PATCHED:18 ms
> pg_walfile_name_offset() - no internal source code callers, no test coverage.
> aclexplode() - internal callers exists information_schema.sql,
> indirect test coverage exists.
> pg_stat_file() - no internal source code callers, test coverage
> exists, test times on HEAD:42 ms PATCHED:46 ms
> pg_get_publication_tables() - internal source code callers exist, test
> coverage exists, test times on HEAD:159 ms, subscription 108 wallclock
> secs PATCHED:167 ms, subscription 110 wallclock secs
> pg_lock_status() - no internal source code callers, test coverage
> exists, test times on HEAD:16 ms PATCHED:22 ms
> pg_stat_get_subscription_stats() - no internal source code callers,
> test coverage exists, test times on HEAD:subscription 108 wallclock
> secs PATCHED:subscription 110 wallclock secs

These ones could be involved in monitoring queries run on a periodic
basis.
--
Michael