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  1. MariaDB Server
  2. MDEV-7486

Condition pushdown from HAVING into WHERE

Details

    Description

      Consider a query 

      SELECT agg_func(...), ... 
      FROM table ... WHERE ... 
      GROUP BY col 
      HAVING cond1(col) AND cond2(agg_func(...))

      Here, cond1(col) can be pushed down from HAVING into WHERE clause. cond2(agg_func(..)) cannot be pushed down.

      Basically, we can push down conditions that remain constant across the GROUP BY groups. Pushdown allows to filter out the whole groups.

      This task is about

      • splitting the condition that can be pushed down
      • moving from HAVING into WHERE, adjusting it appropriately

      Attachments

        Issue Links

          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-18668 Server crash or ASAN use-after-poison in Item_equal_iterator / st_select_lex::pushdown_from_having_into_where upon query with impossible WHERE condition

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-18675 Server crashes in COND_EQUAL::copy

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-18937 Wrong result caused by equality pushdown from HAVING

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-19025 No 'Impossible WHERE' message after pushdown when OR cond is used

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

          Epic - Created by Jira Software - do not edit or delete. Issue type for a big user story that needs to be broken down. MDEV-10137 Providing compatibility to other databases

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

          Task - A task that needs to be done. MDEV-4517 Upper query conditions push down to (aggregated) VIEWs

          • Major - Major loss of function.
          • Closed

          Task - A task that needs to be done. MDEV-12387 Push conditions into materialized IN subqueries

          • Major - Major loss of function.
          • Closed

          Task - A task that needs to be done. MDEV-4571 CLOSE - Query cache like features

          • Trivial - Cosmetic problem like misspelt words or misaligned text.
          • Closed

          Task - A task that needs to be done. MDEV-9197 Pushdown conditions into non-mergeable views/derived tables

          • Major - Major loss of function.
          • Closed

          Activity

            People

              shagalla Galina Shalygina (Inactive)
              psergei Sergei Petrunia
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              Dates

                Created:
                Updated:
                Resolved:

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