When we decide that we don't want to track execution time of a
specific planner or ProcessUtility call, we still have to increment
the nesting depth, or we'll make the wrong determination of whether
we are at top level when considering nested statements. (PREPARE
and EXECUTE are exceptions, for reasons explained in the code.)
Counting planner nesting depth separately from executor nesting depth
was a mistake: it causes us to make the wrong determination of whether
we are at top level when considering nested statements that get
executed during planning (as a result of constant-folding of
functions, for example). Merge those counters into one.
In passing, get rid of the PGSS_HANDLED_UTILITY macro in favor of
explicitly listing statement types. It seems somewhat coincidental
that PREPARE and EXECUTE are handled alike in each of the places where
that was used: the reasoning tends to be different for each one.
Thus, the macro seems as likely to encourage future bugs as prevent
them, since it's quite unclear whether any future statement type that
might need special-casing here would also need the same choices at
each spot.
Sergei Kornilov, Julien Rouhaud, and Tom Lane, per bug #17552 from
Maxim Boguk. This is pretty clearly a bug fix, but it's also a
behavioral change that might surprise somebody, so no back-patch.
Discussion: https://postgr.es/m/17552-213b534c56ab5d02@postgresql.org
As shaped, two DROP ROLE queries included in "user_activity" were
showing in the reports for "wal". The intention is to keep each test
isolated and independent, so this is incorrect. This commit adds some
calls to pg_stat_statements_reset() to clean up the statistics once each
test finishes, so as there are no risks of overlap in the reports for
individial scenarios.
The addition in "user_activity" fixes the output of "wal". The new
resets done in "level_tracking" and "utility" are added for consistency
with the rest, though they do not affect the stats generated in the
other tests.
Oversight in d0028e3.
Reported-by: Andrei Zubkov
Discussion: https://postgr.es/m/7beb722dd016bf54f1c78bfd6d44a684e28da624.camel@moonset.ru
pg_stat_statements.sql acts as the main file for all the core tests of
the module, but things have become complicated to follow over the years
as some of the sub-scenarios tested in this file rely on assumptions
that come from completely different areas of it, like a GUC setup or a
relation created previously. For example, row tracking for CTAS/COPY
was looking at the number of plans, which was not necessary, or level
tracking was mixed with checks on planner counts.
This commit refactors the tests of pg_stat_statements, by moving test
cases out of pg_stat_statements.sql into their own file, as of:
- Planning-related tests in planning.sql, for [re]plan counts and
top-level handling. These depend on pg_stat_statements.track_planning.
- Utilities in utility.sql (pg_stat_statements.track_utility), that
includes now the tests for:
-- Row tracking for CTAS, CREATE MATERIALIZED VIEW, COPY.
-- Basic utility statements.
-- SET statements.
- Tracking level, depending on pg_stat_statements.track. This part has
been looking at scenarios with DO blocks, PL functions and SQL
functions.
pg_stat_statements.sql (still named the same for now) still includes
some checks for role-level tracking and WAL generation metrics, that
ought to become independent in the long term for clarity.
While on it, this switches the order of the attributes when querying
pg_stat_statements, the query field becoming last. This makes much
easier the tracking of changes related to normalization, as queries are
the only variable-length attributes queried (unaligned mode would be one
extra choice, but that reduces the checks on the other fields).
Test scenarios and their results match exactly with what was happening
before this commit in terms of calls, number of plans, number of rows,
cached data or level tracking, so this has no effect on the coverage in
terms of what is produced by the reports in the table
pg_stat_statements. A follow-up patch will extend more the tests of
pg_stat_statements around utilities, so this split creates a foundation
for this purpose, without complicating more pg_stat_statements.sql.
Reviewed-by: Bertrand Drouvot
Discussion: https://postgr.es/m/Y+MRdEq9W9XVa2AB@paquier.xyz
Tom Lane
Michael Paquier