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  1. MariaDB Server
  2. MDEV-34993

Incorrect cardinality estimation causes poor query plan

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    Description

      Filing this based on investigation in TODO-4922.

      There is a class of known issues one can observe with optimizer_use_condition_selectivity=3 setting. MariaDB 11.0 has a rewrite of relevant code.

      This MDEV is about making a minimal fix to stop pre-11.0 versions from picking very poor query plans.

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          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-35074 main.selectivity_notembedded and main.selectivity_innodb_notembedded fail with view protocol

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

          Activity

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            View 4 older comments
            lstartseva Lena Startseva added a comment -

            Testing done. Ok to push.

            lstartseva Lena Startseva added a comment - Testing done. Ok to push.
            psergei Sergei Petrunia added a comment -

            Pushed into 10.5. It would be nice to manually merge to 11.x but currently there's a lot of unmerged stuff which has a lot of conflicts.

            psergei Sergei Petrunia added a comment - Pushed into 10.5. It would be nice to manually merge to 11.x but currently there's a lot of unmerged stuff which has a lot of conflicts.
            marko Marko Mäkelä added a comment -

            Merged to 11.2

            marko Marko Mäkelä added a comment - Merged to 11.2
            monty Michael Widenius added a comment -

            A quick note about this MDEV:
            This patch is only relevant for 10.5 - 10.11. 11.0 and above does not need it as the selectivity code was already fixed.
            This was taking into consideration by Marko and Sergei when doing the merge to 11.2.

            monty Michael Widenius added a comment - A quick note about this MDEV: This patch is only relevant for 10.5 - 10.11. 11.0 and above does not need it as the selectivity code was already fixed. This was taking into consideration by Marko and Sergei when doing the merge to 11.2.
            monty Michael Widenius added a comment -

            Fix pushed to 10.5 tree by Sergei

            monty Michael Widenius added a comment - Fix pushed to 10.5 tree by Sergei

            People

              psergei Sergei Petrunia
              psergei Sergei Petrunia
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                Updated:
                Resolved:

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