Re: [HACKERS] Speedups
От | ocie@paracel.com |
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Тема | Re: [HACKERS] Speedups |
Дата | |
Msg-id | 9803041857.AA25703@dolomite.paracel.com обсуждение исходный текст |
Ответ на | Speedups (jwieck@debis.com (Jan Wieck)) |
Ответы |
Re: [HACKERS] Speedups
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Список | pgsql-hackers |
Jan Wieck wrote: > > Hi, > > just to let anyone know: > > I did some analyzing and searched for areas that could gain > more speedups for 6.4. First I had something like an > optimizer cache in mind (planner remembers parsetree and if a > subsequent parsetree only differs in const values, substitute > consts by params and reuse saved plans instead of creating a > new plan all the time). > > But this is what I got for the complete regression test (only > queries that went through the planner counted): > > Parsing and rule rewriting 14 % > Optimizer and planning 6 % > Query execution 80 % > ------ > Total time in backend 100 % > > It clearly shows that there's no need to speedup the > optimizer. The parser and the executor are the ones that > consume the time. Making the planner/optimizer smarter > resulting better plans faster to execute is the way. This may sound like an obvious question, but if a user defines a query, do we save the query plan? This would reduce the communications between the client and server (a small gain), and allow the server to start executing the query as soon as it recognized the name of the stored query and parsed the arguments. Ocie Mitchell
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