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Re: Analyze all plans - Mailing list pgsql-hackers

From Oleksandr Shulgin
Subject Re: Analyze all plans
Date
Msg-id CACACo5RzQKzdyJmERHb9dL+XWW=DsyM+S4KBoawUVs8v==NKoA@mail.gmail.com
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In response to Analyze all plans  (Donald Dong <xdong@csumb.edu>)
Responses Re: Analyze all plans  (Tom Lane <tgl@sss.pgh.pa.us>)
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On Wed, Jan 23, 2019 at 9:44 AM Donald Dong <xdong@csumb.edu> wrote:

1. Enumerate all the plans

Not sure this is going to work.  Because of the total number of possible plans is somewhere
around O(n!), if I'm not mistaken, in terms of number of joined relations times the available
access methods times the possible join strategies.

So enumerating all possible plans stops being practical for even slightly complicated queries.

Regards,
--
Alex

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