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Re: Multiple-Table-Spanning Joins with ORs in WHERE Clause - Mailing list pgsql-performance

From Pavel Stehule
Subject Re: Multiple-Table-Spanning Joins with ORs in WHERE Clause
Date
Msg-id CAFj8pRCRooD2--9T2uQ8+A9X1v-ToM0VBkJmWoNuR8e4R9dgiQ@mail.gmail.com
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In response to Re: Multiple-Table-Spanning Joins with ORs in WHERE Clause  ("Sven R. Kunze" <srkunze@mail.de>)
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2016-09-29 20:49 GMT+02:00 Sven R. Kunze <srkunze@mail.de>:
On 29.09.2016 20:12, Pavel Stehule wrote:
In ideal world then plan should be independent on used form. The most difficult is safe estimation of OR predicates. With correct estimation the transformation to UNION form should not be necessary I am think.

 Ah, okay. That's interesting.

So how can I help here?

try to write a patch :) or better, help with enhancing PostgreSQL's estimation model. Tomas Vondra is working 2 years on multicolumn statistics. He needs help with review.

Regards

Pavel

Regards,
Sven



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