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revno: 2779 [merge]
committer: Sergey Petrunya <psergey@askmonty.org>
branch nick: maria-5.3-subqueries-r7
timestamp: Mon 2010-03-15 18:09:35 +0300
message:
  Merge in MWL#68: Subquery optimization: Efficient NOT IN execution with NULLs
    ------------------------------------------------------------
    revno: 2761.1.7 [merge]
    committer: Timour Katchaounov <timour@sun.com>
    branch nick: 5.3-mwl68-merge
    timestamp: Mon 2010-03-15 16:34:56 +0200
    message:
      MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

        Automerge with 5.3-subqueries
    ------------------------------------------------------------
    revno: 2761.1.6
    committer: timour@askmonty.org
    branch nick: 5.3-mwl68
    timestamp: Thu 2010-03-11 23:43:31 +0200
    message:
      MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

      This patch does three things:
      - It adds the possibility to force the execution of top-level [NOT] IN
        subquery predicates via the IN=>EXISTS transformation. This is done by
        setting both optimizer switches partial_match_rowid_merge and
        partial_match_table_scan to "off".
      - It adjusts all test cases where the complete optimizer_switch is
        selected because now we have two more switches.
      - For those test cases where the plan changes because of the new available
        strategies, we switch off both partial match strategies in order to
        force the "old" IN=>EXISTS strategy. This is done because most of these
        test cases specifically test bugs in this strategy.
    ------------------------------------------------------------
    revno: 2761.1.5 [merge]
    committer: timour@askmonty.org
    branch nick: 5.3-mwl68-merge.base-mwl68
    timestamp: Tue 2010-03-09 12:36:15 +0200
    message:
      MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

      Automerge with 5.3-subqueries
    ------------------------------------------------------------
    revno: 2761.1.4
    committer: timour@askmonty.org
    branch nick: 5.3-mwl68
    timestamp: Tue 2010-03-09 12:14:06 +0200
    message:
      MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

      * Implemented a second partial matching strategy via table scan.
        This strategy is a fallback when there is no memory for rowid merging.

      * Refactored the selection and creation of partial matching strategies,
        so that the choice of strategy is encapsulated in a separate method
        choose_partial_match_strategy().

      * Refactored the representation of partial match strategies so that:
        - each strategy is represented by a polymorphic class, and
        - the base class for all partial match strategies contains common
          execution code.

      * Added an estimate of the memory needed for the rowid merge strategy,
        and the system variable "rowid_merge_buff_size" to control the maximum
        memory to be used by the rowid merge algorithm.

      * Added two optimizer_switch system variables to control the choice of
        partial match strategy:
        "partial_match_rowid_merge", "partial_match_table_scan".

      * Fixed multiple problems with deallocation of resources by the partial
        match strategies.
    ------------------------------------------------------------
    revno: 2761.1.3
    committer: timour@askmonty.org
    branch nick: 5.3-mwl68-unmerged
    timestamp: Mon 2010-02-22 17:16:55 +0200
    message:
      MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

      This patch mainly adds sorting of all indexes for partial matching
      according to their NULL selectivity. The patch also fixes a related bug
      in subselect_rowid_merge_engine::test_null_row() where the wrong matched
      indexes were skipped.

      In addition the patch:
      - adds few ::print() methods,
      - renames few variables that had similar names but different purpose.
    ------------------------------------------------------------
    revno: 2761.1.2 [merge]
    committer: timour@askmonty.org
    branch nick: 5.3-mwl68-unmerged
    timestamp: Mon 2010-02-22 15:57:09 +0200
    message:
      Automerge with 5.3-subqueries
    ------------------------------------------------------------
    revno: 2761.1.1
    committer: timour@askmonty.org
    branch nick: 5.3-mwl68
    timestamp: Fri 2010-02-19 23:55:57 +0200
    message:
      MWL#68 Subquery optimization: Efficient NOT IN execution with NULLs

      This patch implements correct NULL semantics for materialized subquery execution.
      The implementation has the following properties and main limitations:
      - It passes all query result tests, but fails a number of EXPLAIN tests because of
        changed plans.
      - The EXPLAIN output for partial matching is not decided yet.
      - It works only when all necessary indexes fit into main memory. Notice that these
        are not the general B-tree/Hash indexes, but instead much more compact ones,
        therefore this limitation may not be a problem in many practical cases.
      - It doesn't contain specialized tests.
      - In several places the implementation uses methods that are modified copies of
:
        other similar methods. These cases need to be refactored to avoid code duplication.
      - Add a test if the predicate is top-level just before deciding on partial matching.
        If it is top-level, use a more efficient exec method (index lookup).
      - Add sorting of indexes according to their selectivity. The code is almost there.
      - Needs more comments, and to sync existing ones with the implementation.
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revno: 2778 [merge]
committer: Sergey Petrunya <psergey@askmonty.org>
branch nick: maria-5.3-subqueries-r7-rel
timestamp: Mon 2010-03-15 09:35:35 +0300
message:
  Merge
    ------------------------------------------------------------
    revno: 2776.1.1
    committer: Sergey Petrunya <psergey@askmonty.org>
    branch nick: maria-5.3-subqueries-r7
    timestamp: Mon 2010-03-15 09:06:59 +0300
    message:
      Update test results for the previous push
------------------------------------------------------------
revno: 2777
committer: Sergey Petrunya <psergey@askmonty.org>
branch nick: maria-5.3-subqueries-r7-rel
timestamp: Mon 2010-03-15 09:32:54 +0300
message:
  Apply fix by Roy Lyseng:
  Bug#48623: Multiple subqueries are optimized incorrectly

  The function setup_semijoin_dups_elimination() has a major loop that
  goes through every table in the JOIN object. Usually, there is a normal
  "plus one" increment in the for loop that implements this, but each semijoin
  nest is treated as one entity and there is another increment that skips past
  the semijoin nest to the next table in the JOIN object. However, when
  combining these two increments, the next joined table is skipped, and if that
  happens to be the start of another semijoin nest, the correct processing
  for that nest will not be carried out.
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