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  1. MariaDB Server
  2. MDEV-7486

Condition pushdown from HAVING into WHERE

        Details

        • Type: Task
        • Status: Open
        • Priority: Major
        • Resolution: Unresolved
        • Fix Version/s: 10.2
        • Component/s: Optimizer
        • Labels:
          None

          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

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                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.
                • Stalled

                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

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                    People

                    • Assignee:
                      sanja Oleksandr Byelkin
                      Reporter:
                      psergey Sergei Petrunia
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                      Dates

                      • Created:
                        Updated: