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  1. MariaDB Server
  2. MDEV-6929

Port Facebook Prefix Index Queries Optimization

Details

    Description

      https://github.com/facebook/mysql-5.6

      commit e8f0052f9b112dc786bf9b957ed5b16a5749f7fd
      commit e8f0052f9b112dc786bf9b957ed5b16a5749f7fd
      commit 154c579b828a60722a7d9477fc61868c07453d08

      Port v5.1 Prefix Index Queries Optimization

      Summary:
      Feature: Prefix Index Queries Optimization

      Optimize prefix index queries to skip cluster index lookup when possible.

      Currently InnoDB will always fetch the clustered index (primary key
      index) for all prefix columns in an index, even when the value of a
      particular record is smaller than the prefix length. This change
      optimizes that case to use the record from the secondary index and avoid
      the extra lookup.

      Also adds two status vars that track how effective this is:

      innodb_secondary_index_triggered_cluster_reads:
      Times secondary index lookup triggered cluster lookup.

      innodb_secondary_index_triggered_cluster_reads_avoided:
      Times prefix optimization avoided triggering cluster lookup.

      Attachments

        Issue Links

          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-12255 innodb_prefix_index_cluster_optimization hits debug build assert on UTF-8 columns

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-12486 Incorrect results with prefix_index_cluster_optimization enabled

          • Major - Major loss of function.
          • Closed
          is part of

          Task - A task that needs to be done. MDEV-6039 WebScaleSQL patches

          • Major - Major loss of function.
          • Closed
          relates to

          Task - A task that needs to be done. MDEV-28540 Deprecate and ignore the parameter innodb_prefix_index_cluster_optimization

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-25440 Assertion `cmp_rec_rec(rec, old_rec, offsets, old_offsets, m_index) > 0' failed in PageBulk::insert

          • Major - Major loss of function.
          • Closed

          Activity

            jplindst Jan Lindström (Inactive) added a comment -

            commit cb37c557688e2f7f0381d02f78976a1b7d1bfd65
            Author: Jan Lindström <jan.lindstrom@skysql.com>
            Date: Mon Nov 3 11:18:52 2014 +0200

            MDEV-6929: Port Facebook Prefix Index Queries Optimization

            Merge Facebook commit 154c579b828a60722a7d9477fc61868c07453d08
            and e8f0052f9b112dc786bf9b957ed5b16a5749f7fd authored
            by Steaphan Greene from https://github.com/facebook/mysql-5.6

            Optimize prefix index queries to skip cluster index lookup when possible.

            Currently InnoDB will always fetch the clustered index (primary key
            index) for all prefix columns in an index, even when the value of a
            particular record is smaller than the prefix length. This change
            optimizes that case to use the record from the secondary index and avoid
            the extra lookup.

            Also adds two status vars that track how effective this is:

            innodb_secondary_index_triggered_cluster_reads:
            Times secondary index lookup triggered cluster lookup.

            innodb_secondary_index_triggered_cluster_reads_avoided:
            Times prefix optimization avoided triggering cluster lookup.

            jplindst Jan Lindström (Inactive) added a comment - commit cb37c557688e2f7f0381d02f78976a1b7d1bfd65 Author: Jan Lindström <jan.lindstrom@skysql.com> Date: Mon Nov 3 11:18:52 2014 +0200 MDEV-6929 : Port Facebook Prefix Index Queries Optimization Merge Facebook commit 154c579b828a60722a7d9477fc61868c07453d08 and e8f0052f9b112dc786bf9b957ed5b16a5749f7fd authored by Steaphan Greene from https://github.com/facebook/mysql-5.6 Optimize prefix index queries to skip cluster index lookup when possible. Currently InnoDB will always fetch the clustered index (primary key index) for all prefix columns in an index, even when the value of a particular record is smaller than the prefix length. This change optimizes that case to use the record from the secondary index and avoid the extra lookup. Also adds two status vars that track how effective this is: innodb_secondary_index_triggered_cluster_reads: Times secondary index lookup triggered cluster lookup. innodb_secondary_index_triggered_cluster_reads_avoided: Times prefix optimization avoided triggering cluster lookup.

            People

              jplindst Jan Lindström (Inactive)
              jplindst Jan Lindström (Inactive)
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                Updated:
                Resolved:

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