2 Commits (d66a922f9247ceaa6caed9b51ce686f12e280091)

Author	SHA1	Message	Date
Michael Paquier	290e8ab32a	pg_stat_statements: Fix parameter number gaps in normalized queries ... pg_stat_statements anticipates that certain constant locations may be recorded multiple times and attempts to avoid calculating a length for these locations in fill_in_constant_lengths(). However, during generate_normalized_query() where normalized query strings are generated, these locations are not excluded from consideration. This could increment the parameter number counter for every recorded occurrence at such a location, leading to an incorrect normalization in certain cases with gaps in the numbers reported. For example, take this query: SELECT WHERE '1' IN ('2'::int, '3'::int::text) Before this commit, it would be normalized like that, with gaps in the parameter numbers: SELECT WHERE $1 IN ($3::int, $4::int::text) However the correct, less confusing one should be like that: SELECT WHERE $1 IN ($2::int, $3::int::text) This commit fixes the computation of the parameter numbers to track the number of constants replaced with an $n by a separate counter instead of the iterator used to loop through the list of locations. The underlying query IDs are not changed, neither are the normalized strings for existing PGSS hash entries. New entries with fresh normalized queries would automatically get reshaped based on the new parameter numbering. Issue discovered while discussing a separate problem for HEAD, but this affects all the stable branches. Author: Sami Imseih <samimseih@gmail.com> Discussion: https://postgr.es/m/CAA5RZ0tzxvWXsacGyxrixdhy3tTTDfJQqxyFBRFh31nNHBQ5qA@mail.gmail.com Backpatch-through: 13	7 months ago
Michael Paquier	7db9bfc1f7	Add missing query ID reporting in extended query protocol ... This commit adds query ID reports for two code paths when processing extended query protocol messages: - When receiving a bind message, setting it to the first Query retrieved from a cached cache. - When receiving an execute message, setting it to the first PlannedStmt stored in a portal. An advantage of this method is that this is able to cover all the types of portals handled in the extended query protocol, particularly these two when the report done in ExecutorStart() is not enough (neither is an addition in ExecutorRun(), actually, for the second point): - Multiple execute messages, with multiple ExecutorRun(). - Portal with execute/fetch messages, like a query with a RETURNING clause and a fetch size that stores the tuples in a first execute message going though ExecutorStart() and ExecuteRun(), followed by one or more execute messages doing only fetches from the tuplestore created in the first message. This corresponds to the case where execute_is_fetch is set, for example. Note that the query ID reporting done in ExecutorStart() is still necessary, as an EXECUTE requires it. Query ID reporting is optimistic and more calls to pgstat_report_query_id() don't matter as the first report takes priority except if the report is forced. The comment in ExecutorStart() is adjusted to reflect better the reality with the extended query protocol. The test added in pg_stat_statements is a courtesy of Robert Haas. This uses psql's \bind metacommand, hence this part is backpatched down to v16. Reported-by: Kaido Vaikla, Erik Wienhold Author: Sami Imseih Reviewed-by: Jian He, Andrei Lepikhov, Michael Paquier Discussion: https://postgr.es/m/CA+427g8DiW3aZ6pOpVgkPbqK97ouBdf18VLiHFesea2jUk3XoQ@mail.gmail.com Discussion: https://postgr.es/m/CA+TgmoZxtnf_jZ=VqBSyaU8hfUkkwoJCJ6ufy4LGpXaunKrjrg@mail.gmail.com Discussion: https://postgr.es/m/1391613709.939460.1684777418070@office.mailbox.org Backpatch-through: 14	1 year ago