[PERFORM] partitioning performance question

2012-06-09 Thread Kevin Kempter
Hi All; We have a client that has a table where large blobs (bytea) are stored. the table has a key column that is numbers (like 112362) but unfortunately it's a varchar column so the blobs are accessed via queries like: select * from bigtable where keycol = '217765' The primary reason we

[PERFORM] Update join performance issues

2012-04-03 Thread Kevin Kempter
Hi All; I have a query that wants to update a table based on a join like this: update test_one set f_key = t.f_key from upd_temp1 t, test_one t2 where t.id_number = t2.id_number upd_temp1 has 248,762 rows test_one has 248,762 rows test_one has an index on f_key and an index on

Re: [PERFORM] slow DDL creation

2010-08-31 Thread Kevin Kempter
On Monday 30 August 2010 17:04, bricklen wrote: On Mon, Aug 30, 2010 at 3:28 PM, Kevin Kempter cs_...@consistentstate.com wrote: Hi all ; we have an automated partition creation process that includes the creation of an FK constraint. we have a few other servers with similar scenarios

[PERFORM] slow DDL creation

2010-08-30 Thread Kevin Kempter
Hi all ; we have an automated partition creation process that includes the creation of an FK constraint. we have a few other servers with similar scenarios and this is the only server that stinks per when we create the new partitions. Anyone have any thoughts on how to debug this? were

[PERFORM] dates and partitioning

2010-07-20 Thread Kevin Kempter
Hi All; we have a table partitioned by day, the check constraint on the child tables looks like this (this is the may 31st partition): CHECK (stime = '2010-05-30 00:00:00+00'::timestamp with time zone AND stime = '2010-05-30 23:59:59+00'::timestamp with time zone) We have a python based

[PERFORM] prepared statements and partitioning (partition elimination not working)

2010-03-08 Thread Kevin Kempter
Hi all; we've found that partition elimination is not happening for a prepared statement, however running the same statement in psql manually does give us partition elimination. Is this a known issue? -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make

[PERFORM] partitioned tables query not using indexes

2010-02-24 Thread Kevin Kempter
Hi All; I have a table that has daily partitions. The check constraints look like this: CHECK (timezone('EST'::text, insert_dt) = '2010-01-01'::date AND timezone('EST'::text, insert_dt) '2010-01-02'::date) each partition has this index: fact_idx1_20100101_on_cust_id btree (cust_id) If I

Re: [PERFORM] partitioned tables query not using indexes

2010-02-24 Thread Kevin Kempter
On Wednesday 24 February 2010 07:55:36 A. Kretschmer wrote: In response to Kevin Kempter : Hi All; I have a table that has daily partitions. The check constraints look like this: CHECK (timezone('EST'::text, insert_dt) = '2010-01-01'::date AND timezone('EST'::text, insert_dt) '2010

Re: [PERFORM] Massive table (500M rows) update nightmare

2010-01-07 Thread Kevin Kempter
On Thursday 07 January 2010 09:57:59 Kevin Grittner wrote: Ludwik Dylag ldy...@gmail.com wrote: I would suggest: 1. turn off autovacuum 1a. ewentually tune db for better performace for this kind of operation (cant not help here) 2. restart database 3. drop all indexes 4. update

Re: [PERFORM] How exactly does Analyze work?

2009-11-25 Thread Kevin Kempter
On Wednesday 25 November 2009 05:34:26 Richard Neill wrote: Dear All, Thanks very much for your help so far. My understanding of PG is getting a lot better! I wonder if I've understood analyze properly: I'm not sure I quite understand how specific the statistics gathered actually are.

Re: [PERFORM] partitioning max() sql not using index

2009-09-09 Thread Kevin Kempter
:22 -0400, Heikki Linnakangas heikki.linnakan...@enterprisedb.com wrote: Kevin Kempter wrote: Hi all I have a large table (2billion rows) that's partitioned by date based on an epoch int value. We're running a select max(id) where id is the PK. I have a PK index on each

[PERFORM] partitioning max() sql not using index

2009-09-08 Thread Kevin Kempter
Hi all I have a large table (2billion rows) that's partitioned by date based on an epoch int value. We're running a select max(id) where id is the PK. I have a PK index on each of the partitions, no indexes at all on the base table. If I hit a partition table directly I get an index scan as

[PERFORM] partition queries hitting all partitions even though check key is specified

2009-09-02 Thread Kevin Kempter
Hi all; I cant figure out why we're scanning all of our partitions. We setup our tables like this: Base Table: CREATE TABLE url_hits ( id integer NOT NULL, content_type_id integer, file_extension_id integer, time integer, bytes integer NOT NULL, path_id integer,

Re: [PERFORM] partition queries hitting all partitions even though check key is specified

2009-09-02 Thread Kevin Kempter
On Wednesday 02 September 2009 09:02:27 Scott Marlowe wrote: On Wed, Sep 2, 2009 at 8:52 AM, Kevin Kempterkev...@consistentstate.com wrote: Hi all; I cant figure out why we're scanning all of our partitions. We setup our tables like this: Base Table: CREATE TABLE url_hits (

Re: [PERFORM] partition queries hitting all partitions even though check key is specified

2009-09-02 Thread Kevin Kempter
On Wednesday 02 September 2009 08:55:38 Kenneth Marshall wrote: The planner does not yet work as efficiently as it could with child tables. Check the recent mail archives for a long discussion of the same. Regards, Ken On Wed, Sep 02, 2009 at 08:52:30AM -0600, Kevin Kempter wrote: Hi all

[PERFORM] moving data between tables causes the db to overwhelm the system

2009-09-01 Thread Kevin Kempter
Hi all; We have a table that's 2billion rows big and growing fast. We've setup monthly partitions for it. Upon running the first of many select * from bigTable insert into partition statements (330million rows per month) the entire box eventually goes out to lunch. Any thoughts/suggestions?

Re: [PERFORM] moving data between tables causes the db to overwhelm the system

2009-09-01 Thread Kevin Kempter
On Tuesday 01 September 2009 03:26:08 Pierre Frédéric Caillaud wrote: We have a table that's 2billion rows big and growing fast. We've setup monthly partitions for it. Upon running the first of many select * from bigTable insert into partition statements (330million rows per month) the

[PERFORM] improving my query plan

2009-08-20 Thread Kevin Kempter
Hi all; I have a simple query against two very large tables ( 800million rows in theurl_hits_category_jt table and 9.2 million in the url_hits_klk1 table ) I have indexes on the join columns and I've run an explain. also I've set the default statistics to 250 for both join columns. I get a

[PERFORM] Query tuning

2009-08-19 Thread Kevin Kempter
Hi all; we've been fighting this query for a few days now. we bumped up the statistict target for the a.id , c.url_hits_id and the b.id columns below to 250 and ran an analyze on the relevant tables. we killed it after 8hrs. Note the url_hits table has 1.4billion rows Any suggestions?

Re: [PERFORM] Query tuning

2009-08-19 Thread Kevin Kempter
On Wednesday 19 August 2009 11:17:26 Scott Carey wrote: On 8/19/09 9:28 AM, Kevin Kempter kev...@consistentstate.com wrote: Hi all; we've been fighting this query for a few days now. we bumped up the statistict target for the a.id , c.url_hits_id and the b.id columns below to 250

Re: [PERFORM] Query tuning

2009-08-19 Thread Kevin Kempter
On Wednesday 19 August 2009 11:31:30 Nikolas Everett wrote: 2009/8/19 Grzegorz Jaśkiewicz gryz...@gmail.com that seems to be the killer: and time = extract ('epoch' from timestamp '2009-08-12') and time extract ('epoch' from timestamp '2009-08-13' ) You probably need an index on

[PERFORM] performance tuning queries

2008-11-26 Thread Kevin Kempter
Hi All; I'm looking for tips / ideas per performance tuning some specific queries. These are generally large tables on a highly active OLTP system (100,000 - 200,000 plus queries per day) First off, any thoughts per tuning inserts into large tables. I have a large table with an insert like

[PERFORM] Monitoring buffercache...

2008-11-24 Thread Kevin Kempter
Hi All; I've installed pg_buffercache and I want to use it to help define the optimal shared_buffers size. Currently I run this each 15min via cron: insert into buffercache_stats select now(), isdirty, count(*) as buffers, (count(*) * 8192) as memory from pg_buffercache group by 1,2; and

[PERFORM] Federated Postgresql architecture ?

2008-06-26 Thread kevin kempter
Hi List; Anyone have any experiences to share per setting up a federated architecture with PostgreSQL ? I wonder if the dblink contrib works well in a federated scenario, specifically in the setup of the federated views which equate to a select * from the same table on each federated

[PERFORM] slow update

2008-05-20 Thread kevin kempter
Hi all; I have a query that does this: update tab_x set (inactive_dt, last_update_dt) = ((select run_dt from current_run_date), (select run_dt from current_run_date)) where cust_id::text || loc_id::text in (select cust_id::text || loc_id::text from summary_tab); The current_run_date table

[PERFORM] improving performance for a delete

2008-05-20 Thread kevin kempter
Hi all; I have 2 tables where I basically want to delete from the first table (seg_id_tmp7) any rows where the entire row already exists in the second table (sl_cd_segment_dim) I have a query that looks like this (and it's slow): delete from seg_id_tmp7 where

Re: [PERFORM] improving performance for a delete

2008-05-20 Thread kevin kempter
Version 8.3.1 On May 20, 2008, at 1:51 PM, kevin kempter wrote: Hi all; I have 2 tables where I basically want to delete from the first table (seg_id_tmp7) any rows where the entire row already exists in the second table (sl_cd_segment_dim) I have a query that looks like

[PERFORM] Join runs for 10 hours and then fills up 1.3TB of disk space

2008-05-16 Thread kevin kempter
Hi List; I have a table with 9,961,914 rows in it (see the describe of bigtab_stats_fact_tmp14 below) I also have a table with 7,785 rows in it (see the describe of xsegment_dim below) I'm running the join shown below and it takes 10 hours and eventually runs out of disk space on a

Re: [PERFORM] Join runs for 10 hours and then fills up 1.3TB of disk space

2008-05-16 Thread kevin kempter
Also, I'm running version 8.3 on a centOS box with 2 dual core CPU's and 32Gig of ram On May 16, 2008, at 12:58 AM, kevin kempter wrote: Sorry I goofed on the query text Here's the correct query: select f14.xpublisher_dim_id, f14.xtime_dim_id, f14.xlocation_dim_id, f14.xreferrer_dim_id

Re: [PERFORM] Join runs for 10 hours and then fills up 1.3TB of disk space

2008-05-16 Thread kevin kempter
= segdim.episode_srcid and segdim.segment_srcid is NULL; On May 16, 2008, at 12:31 AM, kevin kempter wrote: Hi List; I have a table with 9,961,914 rows in it (see the describe of bigtab_stats_fact_tmp14 below) I also have a table with 7,785 rows in it (see the describe of xsegment_dim below

Re: [PERFORM] Join runs for 10 hours and then fills up 1.3TB of disk space

2008-05-16 Thread kevin kempter
product join. On May 16, 2008, at 1:40 AM, Richard Huxton wrote: kevin kempter wrote: Hi List; I have a table with 9,961,914 rows in it (see the describe of bigtab_stats_fact_tmp14 below) I also have a table with 7,785 rows in it (see the describe of xsegment_dim below) I'm running the join

Re: [PERFORM] Join runs for 10 hours and then fills up 1.3TB of disk space

2008-05-16 Thread kevin kempter
wrote: On Fri, 2008-05-16 at 00:31 -0600, kevin kempter wrote: I'm running the join shown below and it takes 10 hours and eventually runs out of disk space on a 1.4TB file system Well, running in 10 hours doesn't mean there's a software problem, nor does running out of disk space. Please

[PERFORM] seq scan issue...

2008-04-17 Thread kevin kempter
Hi List; I have a large tble (playback_device) with 6million rows in it. The aff_id_tmp1 table has 600,000 rows. I also have this query: select distinct tmp1.affiliate_id, tmp1.name, tmp1.description, tmp1.create_dt, tmp1.playback_device_id, pf.segment_id from aff_id_tmp1 tmp1,

[PERFORM] Partitioned tables - planner wont use indexes

2008-04-10 Thread kevin kempter
Hi List; I'm having some performance issues with a partitioned table. We have a VERY large table that we've partitioned by day. Currently we have 17 partitions - each partition table contains 700million rows. One of the things we need to query is the min date from the master table - we

[PERFORM] Partitioned tables - planner wont use indexes

2008-04-04 Thread kevin kempter
Hi List; Sorry if this is a dupe, my first post never showed up... I'm having some performance issues with a partitioned table. We have a VERY large table that we've partitioned by day. Currently we have 17 partitions - each partition table contains 700million rows. One of the things we

Re: [PERFORM] Query only slow on first run

2007-11-27 Thread Kevin Kempter
On Tuesday 27 November 2007 09:33:36 cluster wrote: I have a query that takes about 7000 ms in average to complete the first time it runs. Subsequent runs complete in only 50 ms. That is more than a factor 100 faster! How can I make the query perform good in the first run too? Query and

[PERFORM] building a performance test suite

2007-10-10 Thread Kevin Kempter
Hi List; I'm preparing to create a test suite of very complex queries that can be profiled in terms of load and performance. The ultimate goal is to define a load/performance profile during a run of the old application code base and then again with changes to the application code base. I

[PERFORM] performance of like queries

2007-10-02 Thread Kevin Kempter
Hi List; any suggestions for improving LIKE '%text%' queries? Thanks in advance ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster

[PERFORM] Tuning for warm standby

2007-09-27 Thread Kevin Kempter
Hi All; I'm preparing to fire up WAL archiving on 8 production servers We will follow up with implementing a warm standby scenariio. Does anyone have any thoughts per how to maximize performance, yet minimize the potential for data loss assuming we were not able to retrieve the final

[PERFORM] More Vacuum questions...

2007-09-11 Thread Kevin Kempter
Hi List; I've recently started cleaning up some postgres db's which previous to my recent arrival had no DBA to care for them. I quickly figured out that there were several tables which were grossly full of dead space. One table in particular had 75G worth of dead pages (or the equivelant in

Re: [PERFORM] significant vacuum issues - looking for suggestions

2007-08-27 Thread Kevin Kempter
On Monday 27 August 2007 15:56:33 Kevin Grittner wrote: Decibel! [EMAIL PROTECTED] 08/27/07 4:00 PM They're running version 8.1.4 As for your pg_dump idea... why not just do a CREATE TABLE AS SELECT * FROM bloated_table? That would likely be much faster than messing around with

Re: [PERFORM] significant vacuum issues - looking for suggestions

2007-08-27 Thread Kevin Kempter
On Monday 27 August 2007 15:00:41 you wrote: On Fri, Aug 24, 2007 at 04:41:44PM -0400, Bill Moran wrote: In response to Kevin Kempter [EMAIL PROTECTED]: Hi List; I've just started working with a client that has been running Postgres (with no DBA) for a few years. They're running

Re: [PERFORM] significant vacuum issues - looking for suggestions

2007-08-27 Thread Kevin Kempter
On Monday 27 August 2007 16:04:39 Decibel! wrote: On Mon, Aug 27, 2007 at 04:56:33PM -0500, Kevin Grittner wrote: Decibel! [EMAIL PROTECTED] 08/27/07 4:00 PM They're running version 8.1.4 As for your pg_dump idea... why not just do a CREATE TABLE AS SELECT * FROM

[PERFORM] server performance issues - suggestions for tuning

2007-08-27 Thread Kevin Kempter
Hi List; I've just inherited multiple postgres database servers in multiple data centers across the US and Europe via a new contract I've just started. Each night during the nightly batch processing several of the servers (2 in particular) slow to a crawl - they are dedicated postgres database

[PERFORM] significant vacuum issues - looking for suggestions

2007-08-24 Thread Kevin Kempter
Hi List; I've just started working with a client that has been running Postgres (with no DBA) for a few years. They're running version 8.1.4 on 4-way dell boxes with 4Gig of memory on each box attached to RAID-10 disk arrays. Some of their key config settings are here: shared_buffers = 20480

Re: [PERFORM] significant vacuum issues - looking for suggestions

2007-08-24 Thread Kevin Kempter
On Friday 24 August 2007 15:39:22 Tom Lane wrote: Kevin Kempter [EMAIL PROTECTED] writes: The development folks that have been here awhile tell me that it seems like when they have a query (not limited to vacuum processes) that has been running for a long time (i.e. 5 or 6 hours

[PERFORM] long-running query - needs tuning

2007-08-23 Thread Kevin Kempter
Hi List; I've just started working with a new client and they have amoung other issues with their databases a particular update that basically locks out users. The below query was running for over 6 hours this morning and the CPU load had climbed to a point where new connections simply hung

[PERFORM] Questions about planner methods

2006-12-24 Thread Kevin Kempter
Hi List(s); I'm wanting to find more details per the following methods, can someone explain to me exactly what each of these methods is, how its implemented in postgres or point me to some docs or README's that explain these methods? Some of 'em are obviously no-brainers but I'm writing a

[PERFORM] OT - how to size/match multiple databases/apps for a single server

2006-11-29 Thread Kevin Kempter
Hi List; I have a client looking to host/co-locate multiple PostgreSQL clusters (inclusive of PL/pgSQL application code) per server. I did some co-location work several years back with one of the bigger telco's and remember there were dire consequences for not carefully evaluating the expected