[PERFORM] More speed counting rows

Hello, I am trying to optimize the count of files when I am using filters (select by some row/s parameter/s) In this case I think that postgresql really count all files. Resulting in unacceptable times of 4 seconds in http server response. Triggers+store in this case do not see very acceptable,

Re: [PERFORM] Can Postgres use an INDEX over an OR?

2009/7/20 Віталій Тимчишин tiv...@gmail.com: 20 липня 2009 р. 11:02 Chris dmag...@gmail.com написав: Віталій Тимчишин wrote: 2009/7/20 Robert James srobertja...@gmail.com mailto:srobertja...@gmail.com    Hi. I notice that when I do a WHERE x, Postgres uses an index, and    when I do

Re: [PERFORM] Very big insert/join performance problem (bacula)

It really has very little impact. It only affects index scans, and even then only if effective_cache_size is less than the size of the table. Essentially, when this kicks in, it models the effect that if you are index scanning a table much larger than the size of your cache, you might have

Re: [PERFORM] Can Postgres use an INDEX over an OR?

27 липня 2009 р. 13:53 Robert Haas robertmh...@gmail.com написав: Hmm. What you're suggesting here is that we could consider implementing OR conditions by rescanning the inner side for each index qual and then unique-ifying the results on the index column. That's probably possible, but it

Re: [PERFORM] Can Postgres use an INDEX over an OR?

2009/7/27 Віталій Тимчишин tiv...@gmail.com: 27 липня 2009 р. 13:53 Robert Haas robertmh...@gmail.com написав: Hmm.  What you're suggesting here is that we could consider implementing OR conditions by rescanning the inner side for each index qual and then unique-ifying the results on the

Re: [PERFORM] Can Postgres use an INDEX over an OR?

27 липня 2009 р. 15:02 Robert Haas robertmh...@gmail.com написав: The problem, though, is that it won't ALWAYS be right to implement OR using UNION, so you have to have some way of deciding which is better. That's easy - you propose both ways to planner and it's up to it to decide. Yes, it

Re: [PERFORM] More speed counting rows

On Mon, Jul 27, 2009 at 3:06 AM, Developerdev...@pas-world.com wrote: Hello, I am trying to optimize the count of files when I am using filters (select by some row/s parameter/s) In this case I think that postgresql really count all files. Resulting in unacceptable times of 4 seconds in

[PERFORM] select query performance question

Hi, subject is the following type of query needed in a function to select data: SELECT ' 13.04.2009 12:00:00 ' AS zeit, 'M' AS

Re: [PERFORM] Can Postgres use an INDEX over an OR?

=?KOI8-U?B?96bUwcymyiD0yc3eydvJzg==?= tiv...@gmail.com writes: Actually what I am talking about is to make OR with UNION (or UNION-like because it's a little different depending on input rows uniqueness) as an option. All of OR parts can use/not use different strategies (including multiple

Re: [PERFORM] select query performance question

Hello maybe is wrong tip, but your function like de* should be slow. What is time of query without calling these functions? Pavel Stehule 2009/7/27 Thomas Zaksek zak...@ptt.uni-due.de: Hi, subject is the following type of query needed in a function to select data: SELECT ' 13.04.2009

Re: [PERFORM] Can Postgres use an INDEX over an OR?

27 липня 2009 р. 17:18 Tom Lane t...@sss.pgh.pa.us написав: =?KOI8-U?B?96bUwcymyiD0yc3eydvJzg==?= tiv...@gmail.com writes: Actually what I am talking about is to make OR with UNION (or UNION-like because it's a little different depending on input rows uniqueness) as an option. All of OR

Re: [PERFORM] select query performance question

On Mon, 27 Jul 2009, Thomas Zaksek wrote: Nested Loop (cost=0.00..66344.47 rows=4750 width=10) (actual time=134.160..19574.228 rows=4148 loops=1) - Index Scan using messungen_v_dat_2009_04_13_gtyp_minute_tag_idx on messungen_v_dat_2009_04_13 m (cost=0.00..10749.14

Re: [PERFORM] select query performance question

Thomas Zaksek zak...@ptt.uni-due.de wrote: Is this query plan near to optimal or are their any serious flaws? I didn't see any problem with the query, but with the information provided, we can't really tell if you need to reconfigure something, or maybe add an index. The plan generated for

Re: [PERFORM] More speed counting rows

Developer wrote: Hello, I am trying to optimize the count of files when I am using filters (select by some row/s parameter/s) In this case I think that postgresql really count all files. Resulting in unacceptable times of 4 seconds in http server response. Triggers+store in this case do not

Re: [PERFORM] More speed counting rows

On Mon, Jul 27, 2009 at 5:06 AM, Developerdev...@pas-world.com wrote: Hello, I am trying to optimize the count of files when I am using filters (select by some row/s parameter/s) My question is: Any method for indirect count like ordered indexes + quadratic count? Any module? Any

Re: [PERFORM] hyperthreaded cpu still an issue in 8.4?

On Mon, 27 Jul 2009, Dave Youatt wrote: Do you think it's due to the new internal interconnect, that bears a strong resemblance to AMD's hypertransport (AMD's buzzword for borrowing lots of interconnect technology from the DEC alpha (EV7?)), or Intel fixing a not-so-good initial

Re: [PERFORM] hyperthreaded cpu still an issue in 8.4?

On 01/-10/-28163 11:59 AM, Greg Smith wrote: On Tue, 21 Jul 2009, Doug Hunley wrote: Just wondering is the issue referenced in http://archives.postgresql.org/pgsql-performance/2005-11/msg00415.php is still present in 8.4 or if some tunable (or other) made the use of hyperthreading a

Re: [PERFORM] More speed counting rows

How up to date do the counts need to be? If the count takes 4 seconds, can you run it every minute and store the counts in a table for retrieval by the HTTP requests? Now, I am storing integer value for filter in memory with timeout, but in busy server, system sure crash without system

Re: [PERFORM] hyperthreaded cpu still an issue in 8.4?

On 7/27/09 11:05 AM, Dave Youatt d...@meteorsolutions.com wrote: On 01/-10/-28163 11:59 AM, Greg Smith wrote: On Tue, 21 Jul 2009, Doug Hunley wrote: Also, and this is getting maybe too far off topic, beyond the buzzwords, what IS the new hyperthreading in Nehalems? -- opportunistic

Re: [PERFORM] select query performance question

Hi Thomas, How is 'messungen_v_dat_2009_04_13_gtyp_minute_tag_idx' defined? What is the row count for the table? Mike Hi, subject is the following type of query needed in a function to select data: SELECT ' 13.04.2009 12:00:00 ' AS zeit,

[PERFORM] Will Postgres ever lock with read only queries?

Hi. I'm seeing some weird behavior in Postgres. I'm running read only queries (SELECT that is - no UPDATE or DELETE or INSERT is happening at all). I can run one rather complicated query and the results come back... eventually. Likewise with another. But, when I run both queries at the same

Re: [PERFORM] Will Postgres ever lock with read only queries?

On 07/27/2009 08:54 PM, Robert James wrote: Hi. I'm seeing some weird behavior in Postgres. I'm running read only queries (SELECT that is - no UPDATE or DELETE or INSERT is happening at all). I can run one rather complicated query and the results come back... eventually. Likewise with

Re: [PERFORM] Will Postgres ever lock with read only queries?

Robert James wrote: Hi. I'm seeing some weird behavior in Postgres. I'm running read only queries (SELECT that is - no UPDATE or DELETE or INSERT is happening at all). I can run one rather complicated query and the results come back... eventually. Likewise with another. But, when I run

Re: [PERFORM] Will Postgres ever lock with read only queries?

Chris dmag...@gmail.com writes: Robert James wrote: Hi. I'm seeing some weird behavior in Postgres. I'm running read only queries (SELECT that is - no UPDATE or DELETE or INSERT is happening at all). I can run one rather complicated query and the results come back... eventually.