Re: [HACKERS] Query Optimizer + Parallel Operators
On 26.01.2011 16:46, Felix Schmidt @ Oracle wrote: Everybody, I'm interested in the query optimizer of PostgreSQL DB. Where could I find useful documentation or could you send me a pointer in the source code? The relevant source code is in src/backend/optimizer directory. If you google around, you'll find introductory presentations, but I can't recommend any particular one. What kind of parallelism does PostgreSQL use for operators, like selection or join? The short answer is none. Each PostgreSQL backend is a one single-threaded process, one query will only utilize one CPU (http://wiki.postgresql.org/wiki/FAQ#How_does_PostgreSQL_use_CPU_resources.3F). If you search the archives, you'll find discussion on how it might one day be improved, but nothing concrete has been done. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Query Optimizer + Parallel Operators
Felix, I'm interested in the query optimizer of PostgreSQL DB. Where could I find useful documentation or could you send me a pointer in the source code? What kind of parallelism does PostgreSQL use for operators, like selection or join? Normally we're very helpful with this kind of information ... it's all public after all ... but I have to say that the domain you're e-mailing from makes it a little hard to give you a direct answer. Could you maybe give us a little information about what you want this information for? -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Query Optimizer + Parallel Operators
This is kinda scary . Oracle guy asking for PostgreSQL documentation and internals of the optimizer. On Thu, Jan 27, 2011 at 12:14 AM, Josh Berkus j...@agliodbs.com wrote: Felix, I'm interested in the query optimizer of PostgreSQL DB. Where could I find useful documentation or could you send me a pointer in the source code? What kind of parallelism does PostgreSQL use for operators, like selection or join? Normally we're very helpful with this kind of information ... it's all public after all ... but I have to say that the domain you're e-mailing from makes it a little hard to give you a direct answer. Could you maybe give us a little information about what you want this information for? -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
