Details
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Task
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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None
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Description
If there is a condition that depends only on the second table in a blocked join,
the following blocked join algorithms (BNL, BNLH) use this condition to pre-filter records from this table prior to joining the records.
Currently the optimizer extracts such a single table condition independently from the generic condition pushdown. As a result the same condition may be evaluated up to two times more. This is a problem if the condition is expensive. It also makes it problematic to move the condition to an optimal partial join (see MDEV-83).
Attachments
Issue Links
- blocks
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MDEV-83 Cost-based choice for the pushdown of subqueries to joined tables
- Stalled