Re: [PERFORM] Stored procedure declared as VOLATILE => no good optimization is done

2010-10-16 Thread Merlin Moncure
On Fri, Oct 15, 2010 at 10:31 PM, Tom Lane wrote: > Tatsuo Ishii writes: >> So can I say "if a function is marked IMMUTABLE, then it should never >> modify database"? Is there any counter example? >> It seems if above is correct, I can say STABLE functions should never >> modify databases as well

Re: [PERFORM] UUID performance as primary key

2010-10-16 Thread Merlin Moncure
On Fri, Oct 15, 2010 at 10:59 PM, Craig Ringer wrote: > On 16/10/2010 9:58 AM, Navkirat Singh wrote: >> >> Hi Guys, >> >> I am interested in finding out the pros/cons of using UUID as a primary >> key field. My requirement states that UUID would be perfect in my case as I >> will be having many sm

Re: [PERFORM] Select count(*), the sequel

2010-10-16 Thread Kenneth Marshall
Hi, Interesting data points. The amount of rows that you managed to insert into PostgreSQL before Oracle gave up the ghost is 95% of the rows in the Oracle version of the database. To count 5% fewer rows, it took PostgreSQL 24 seconds longer. Or adjusting for the missing rows, 52 seconds longer fo

Re: [PERFORM] UUID performance as primary key

2010-10-16 Thread Craig James
On 10/15/10 6:58 PM, Navkirat Singh wrote: I am interested in finding out the pros/cons of using UUID as a primary key field. My requirement states that UUID would be perfect in my case as I will be having many small databases which will link up to a global database using the UUID. Hence, the n

[PERFORM] Select count(*), the sequel

2010-10-16 Thread Mladen Gogala
There was some doubt as for the speed of doing the select count(*) in PostgreSQL and Oracle. To that end, I copied the most part of the Oracle table I used before to Postgres. Although the copy wasn't complete, the resulting table is already significantly larger than the table it was copied from

Re: [PERFORM] No hash join across partitioned tables?

2010-10-16 Thread Alvaro Herrera
Excerpts from Samuel Gendler's message of sáb oct 16 02:35:46 -0300 2010: > An issue with automatically analyzing the entire hierarchy is 'abstract' > table definitions. I've got a set of tables for storing the same data at > different granularities of aggregation. Within each granularity, I've