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BUG #15618: Duplicating a join clause breaks index use - Mailing list pgsql-bugs

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Subject BUG #15618: Duplicating a join clause breaks index use
Date
Msg-id 15618-5357e448d7cbeb27@postgresql.org
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Responses Re: BUG #15618: Duplicating a join clause breaks index use
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The following bug has been logged on the website:

Bug reference:      15618
Logged by:          cd a
Email address:      cdalxndr@yahoo.com
PostgreSQL version: 10.3
Operating system:   Windows 10
Description:

Adding a unused join clause to the query, modifies the run time from 50ms to
4seconds.
No columns from the join clause are returned and the joined table is not
used in other places.
The join clause is a duplicate of another one that is used for further
joining.

The joined clause should have been automatically removed as it has no side
effects, thus using indices and optimizing query runtime.

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