Re: add_path optimization
От | Jaime Casanova |
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Тема | Re: add_path optimization |
Дата | |
Msg-id | 3073cc9b0902011034q988d13fxe41f3d0f30a0d891@mail.gmail.com обсуждение исходный текст |
Ответ на | add_path optimization (Robert Haas <robertmhaas@gmail.com>) |
Ответы |
Re: add_path optimization
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Список | pgsql-hackers |
On Sat, Jan 31, 2009 at 11:37 PM, Robert Haas <robertmhaas@gmail.com> wrote: > I've been doing some benchmarking and profiling on the PostgreSQL > query analyzer, and it seems that (at least for the sorts of queries > that I typically run) the dominant cost is add_path(). I've been able > to find two optimizations that seem to help significantly: > > 1. add_path() often calls compare_fuzzy_path_costs() twice on the same > > 2. match_unsorted_outer() adds as many as 5 nested loop joins at a if there are two optimizations maybe two different patches are better to test them individually -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL Asesoría y desarrollo de sistemas Guayaquil - Ecuador Cel. +59387171157
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