Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-3645

LP:671489 - Wrong result with Aria and MRR in maria-5.3-mwl128-dsmrr-cpk

    XMLWordPrintable

Details

    • Bug
    • Status: Closed (View Workflow)
    • Resolution: Not a Bug
    • None
    • None
    • None

    Description

      The following query:

      SELECT count(table1.col_time_key )
      FROM t1 AS table1 JOIN
      ( t2 AS table2 JOIN t2 AS table3 ON table3.col_int_key <= table2.col_int_nokey )
      ON table3.pk < table2.col_int_key ;

      returns a smaller number of rows when executed under optimizer_use_mrr=force with maria-5.3-mwl128-dsmrr-cpk. maria-5.3 returns a correct result. maria-5.3-dsmrr-cpk crashes. Patch for bug 665049 was used for all trees (applied manually if not naturally present). engine_condition_pushdown and mrr_sort_keys do not seem to be involved.

      Note that the EXPLAIN plan is the same with both optimizer_use_mrr="force" and with "disable". No MRR is mentioned, which is a cause for concern. MRR should be reflected in the EXPLAIN anytime it is used.

      Attachments

        Activity

          People

            psergei Sergei Petrunia
            philipstoev Philip Stoev (Inactive)
            Votes:
            0 Vote for this issue
            Watchers:
            0 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved:

              Git Integration

                Error rendering 'com.xiplink.jira.git.jira_git_plugin:git-issue-webpanel'. Please contact your Jira administrators.