Re: [PERFORM] Not Picking Index

2007-02-16 Thread Tom Lane
"George Pavlov" <[EMAIL PROTECTED]> writes: >> In PG 8.2 and up there is a sneakier way to do it that won't acquire >> any more lock than the statement-under-test does: >> >> begin; >> update pg_index set indisvalid = false >> where indexrelid = 'soandso'::regclass; >> explain analyze ...; >> roll

Re: [PERFORM] Not Picking Index

2007-02-16 Thread George Pavlov
> Note the DROP INDEX will acquire exclusive lock on the table, so this > might not be the greatest thing to do in a production environment. > In PG 8.2 and up there is a sneakier way to do it that won't acquire > any more lock than the statement-under-test does: > > begin; > update pg

Re: [PERFORM] Not Picking Index

2007-02-16 Thread Steinar H. Gunderson
On Fri, Feb 16, 2007 at 01:27:46PM -0500, Brad Nicholson wrote: > If the indexed field is an intger, add 0 to it. Won't that also invalidate the statistics? /* Steinar */ -- Homepage: http://www.sesse.net/ ---(end of broadcast)--- TIP 6: explain a

Re: [PERFORM] Not Picking Index

2007-02-16 Thread Brad Nicholson
On Fri, 2007-02-16 at 20:01 +0530, Gauri Kanekar wrote: > > I want the planner to ignore a specific index. > I am testing some query output. For that purpose i dont want the > index. > I that possible to ignore a index by the planner. If the indexed field is an intger, add 0 to it. -- Brad Nic

Fwd: [PERFORM] Not Picking Index

2007-02-16 Thread Mike Gargano
This is very similar to the problem I posted to this list yesterday. Apparently, if you append an empty string to the column data in your WHERE clause it will force the planer to treat it as a filter and not an index cond. It's extremely ugly, but this method doesn't seem to be anymore

Re: [PERFORM] Not Picking Index

2007-02-16 Thread Tom Lane
"Gauri Kanekar" <[EMAIL PROTECTED]> writes: > I want the planner to ignore a specific index. > I am testing some query output. For that purpose i dont want the index. > I that possible to ignore a index by the planner. begin; drop index soandso; explain analyze ...;

Re: [PERFORM] Not Picking Index

2007-02-16 Thread Alvaro Herrera
Gauri Kanekar escribió: > I want the planner to ignore a specific index. > I am testing some query output. For that purpose i dont want the index. > I that possible to ignore a index by the planner. Sure: BEGIN DROP INDEX foo SELECT ROLLBACK -- Alvaro Herrera

Re: [PERFORM] Not Picking Index

2007-02-16 Thread Gauri Kanekar
I want the planner to ignore a specific index. I am testing some query output. For that purpose i dont want the index. I that possible to ignore a index by the planner. On 2/16/07, Michael Fuhr <[EMAIL PROTECTED]> wrote: On Fri, Feb 16, 2007 at 06:26:51PM +0530, Gauri Kanekar wrote: > I want to

Re: [PERFORM] Not Picking Index

2007-02-16 Thread Michael Fuhr
On Fri, Feb 16, 2007 at 06:26:51PM +0530, Gauri Kanekar wrote: > I want to run a Select Query on a table. But i dont want the query to pick a > index defined on that table. > > So can i instruct the planner not to pick that index. Why don't you want the planner to use the index? Is there a speci

[PERFORM] Not Picking Index

2007-02-16 Thread Gauri Kanekar
Hi List, I want to run a Select Query on a table. But i dont want the query to pick a index defined on that table. So can i instruct the planner not to pick that index. -- Regards Gauri