4 Commits (a7024398b80a836a83c00af42c6ab7cc25c12087)

Author	SHA1	Message	Date
Michael Paquier	f85f6ab051	Revert support for improved tracking of nested queries ... This commit reverts the two following commits: - 499edb0974, track more precisely query locations for nested statements. - 06450c7b8c, a follow-up fix of 499edb0974 with query locations. The test introduced in this commit is not reverted. This is proving useful to track a problem that only pgaudit was able to detect. These prove to have issues with the tracking of SELECT statements, when these use multiple parenthesis which is something supported by the grammar. Incorrect location and lengths are causing pg_stat_statements to become confused, failing its job in query normalization with potential out-of-bound writes because the location and the length may not match with what can be handled. A lot of the query patterns discussed when this issue was reported have no test coverage in the main regression test suite, or the recovery test 027_stream_regress.pl would have caught the problems as pg_stat_statements is loaded by the node running the regression tests. A first step would be to improve the test coverage to stress more the query normalization logic. A different portion of this work was done in 45e0ba30fc, with the addition of tests for nested queries. These can be left in the tree. They are useful to track the way inner queries are currently tracked by PGSS with non-top-level entries, and will be useful when reconsidering in the future the work reverted here. Reported-by: Alexander Kozhemyakin <a.kozhemyakin@postgrespro.ru> Discussion: https://postgr.es/m/18947-cdd2668beffe02bf@postgresql.org	3 months ago
Michael Paquier	499edb0974	Track more precisely query locations for nested statements ... Previously, a Query generated through the transform phase would have unset stmt_location, tracking the starting point of a query string. Extensions relying on the statement location to extract its relevant parts in the source text string would fallback to use the whole statement instead, leading to confusing results like in pg_stat_statements for queries relying on nested queries, like: - EXPLAIN, with top-level and nested query using the same query string, and a query ID coming from the nested query when the non-top-level entry. - Multi-statements, with only partial portions of queries being normalized. - COPY TO with a query, SELECT or DMLs. This patch improves things by keeping track of the statement locations and propagate it to Query during transform, allowing PGSS to only show the relevant part of the query for nested query. This leads to less bloat in entries for non-top-level entries, as queries can now be grouped within the same (toplevel, queryid) duos in pg_stat_statements. The result gives a stricter one-one mapping between query IDs and its query strings. The regression tests introduced in 45e0ba30fc produce differences reflecting the new logic. Author: Anthonin Bonnefoy Reviewed-by: Michael Paquier, Jian He Discussion: https://postgr.es/m/CAO6_XqqM6S9bQ2qd=75W+yKATwoazxSNhv5sjW06fjGAtHbTUA@mail.gmail.com	11 months ago
Alexander Korotkov	6ab1dbd26b	Add NOT NULL checking of pg_stat_statements_reset() in tests ... This is preliminary patch. It adds NOT NULL checking for the result of pg_stat_statements_reset() function. It is needed for upcoming patch "Track statement entry timestamp" that will change the result type of this function to the timestamp of a reset performed. Discussion: https://postgr.es/m/flat/72e80e7b160a6eb189df9ef6f068cce3765d37f8.camel%40moonset.ru Author: Andrei Zubkov Reviewed-by: Julien Rouhaud, Hayato Kuroda, Yuki Seino, Chengxi Sun Reviewed-by: Anton Melnikov, Darren Rush, Michael Paquier, Sergei Kornilov Reviewed-by: Alena Rybakina, Andrei Lepikhov	2 years ago
Michael Paquier	e8dbdb15db	Refactor tests of pg_stat_statements for planning, utility and level tracking ... 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	3 years ago