Uploaded image for project: 'MariaDB Server'
  1. MariaDB Server
  2. MDEV-25707

SELECT queries not using index after upgrade to 10.5.9 (from 10.3.21)

    XMLWordPrintable

    Details

      Description

      The following type of query is using where in EXPLAIN instead of index for some large quantity of OR's (i.e. on 10.5.9 uses WHERE, on 10.3.x uses INDEX also on 10.5.9 takes many minutes, on 10.3.x takes seconds)

      query: SELECT col2 FROM mytable WHERE col1=a OR's col1=b ... with lots of OR's

      If we force the query to use the index, "FORCE INDEX(mytable_col1_idx')", then the 10.5.9 query will finish in time similar to 10.3.x

      See attached files to reproduce.

        Attachments

          Activity

            People

            Assignee:
            psergei Sergei Petrunia
            Reporter:
            mpflaum Maria M Pflaum
            Votes:
            0 Vote for this issue
            Watchers:
            5 Start watching this issue

              Dates

              Created:
              Updated:

                Git Integration