Hi, On Mon, Sep 26, 2022 at 03:12:46PM +0900, bt22nakamorit wrote: > > pg_stat_statements module distinguishes queries with different structures, > but some visibly different MERGE queries were combined as one > pg_stat_statements entry. > For example, > MERGE INTO test1 USING test2 ON test1.id = test2.id WHEN MATCHED THEN UPDATE > var = 1; > MERGE INTO test1 USING test2 ON test1.id = test2.id WHEN MATCHED THEN > DELETE; > These two queries have different command types after WHEN (UPDATE and > DELETE), but they were regarded as one entry in pg_stat_statements. > I think that they should be sampled as distinct queries.
Agreed. > I attached a patch file that adds information about MERGE queries on the > documentation of pg_stat_statements, and lines of code that helps with the > calculation of queryid hash value to differentiate MERGE queries. > Any kind of feedback is appreciated. I didn't test the patch (and never looked at MERGE implementation either), but I'm wondering if MergeAction->matched and MergeAction->override should be jumbled too? Also, the patch should contain some extra tests to fully cover MERGE jumbling.
