Re: nested loop semijoin estimates - Mailing list pgsql-hackers

From Tomas Vondra
Subject Re: nested loop semijoin estimates
Date
Msg-id 55735E6E.70604@2ndquadrant.com
Whole thread Raw
In response to Re: nested loop semijoin estimates  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
FWIW, I've repeated the TPC-DS tests on a much larger data set (50GB) 
today, and I see that

(a) 3f59be836c555fa679bbe0ec76de50a8b5cb23e0 (ANTI/SEMI join costing)    changes nothing - there are some small cost
changes,but only in    plans involving semi/anti-joins (which is expected). Nevertheless,    all the plans remain the
same.

(b) 3b0f77601b9f9f3a2e36a813e4cd32c00e0864d6 (add_path fixes)
    This changes join order in one of the queries, with lots of nested    loops (this is the join order change we've
seenin this thread).    Anyway, this is mostly expected consequence of the add_path changes.
 

So both changes seem fine.

--
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



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