threads listlengths 1 275 |
|---|
[
{
"msg_contents": "I don't clearly understand why this happens, but when I try join some \ntables using arrays I end up with:\n\n=# explain select count(*) from urls JOIN rules ON urls.tag && rules.tag;\n QUERY PLAN \n\n------------------------------------------------------... |
[
{
"msg_contents": "Hello,\n\nI just upgraded with pg_dump/restore from PostgreSQL 8.3.11 to 8.4.4 but \nI'm having major performance problems with a query with many left joins. \nProblem is that costs are now very, very, very high (was ok in 8.3). \nAnalyze has been done. Indexes are of course there.\n\n -> ... |
[
{
"msg_contents": "Not sure if anyone else saw this, but it struck me as an interesting\nidea if it could be added to PostgreSQL. GPU accelerated database\noperations could be very... interesting. Of course, this could be\ndifficult to do in a way that usefully increases performance of\nPostgreSQL, but I'll lea... |
[
{
"msg_contents": "Not sure if anyone else saw this, but it struck me as an interesting\nidea if it could be added to PostgreSQL. GPU accelerated database\noperations could be very... interesting. Of course, this could be\ndifficult to do in a way that usefully increases performance of\nPostgreSQL, but I'll lea... |
[
{
"msg_contents": "Hi all ;\n\nwe have an automated partition creation process that includes the creation of \nan FK constraint. we have a few other servers with similar scenarios and this \nis the only server that stinks per when we create the new partitions.\n\nAnyone have any thoughts on how to debug this? ... |
[
{
"msg_contents": "I've created a few user-defined types quite similar to uuid which we\nuse to store various hashes in the database. (The types use binary\nencoding internally, but only expose hexadecimal strings externally.)\n\nThe hashes are roughly equidistributed, so when I do a range query\nwhich is esse... |
[
{
"msg_contents": "Hello,\nI have I query which behave strangely (according to me).\nAccording to the first plan PG makes absolutely unnecessary seq scan on \ntables \"invoices\" and \"domeini\" and etc.\nI thing they should be access only if there are rows from the where. Why \nthe left join executes first?\nT... |
[
{
"msg_contents": "Howdy,\n\nI'm running pgbench with a fairly large # of clients and getting this error in my PG log file.\n\nHere's the command:\n./pgbench -c 1100 testdb -l\n\nI get:\nLOG: could not send data to client: Broken pipe\n\n(I had to modify the pgbench.c file to make it go that high, i changed:\n... |
[
{
"msg_contents": "Hi all. I Have the following query (tested in postgres 8.4 and 9.0rc1)\n\nSELECT distinct event0_.*\nFROM event event0_ inner join account account1_ on\nevent0_.account_id_owner=account1_.account_id\nLEFT OUTER JOIN friend friendcoll2_ ON\naccount1_.account_id=friendcoll2_.friend_account_id\... |
[
{
"msg_contents": "I have a problem with some simple query:\n\nselect version();\n PostgreSQL 8.3.8 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 4.3.2\n20081105 (Red Hat 4.3.2-7)\nvacuum full bug_t1;\nvacuum full bug_t2;\nvacuum analyze bug_t1;\nvacuum analyze bug_t2;\nexplain analyze SELECT ze.id ,rr.id FRO... |
[
{
"msg_contents": "\nI have a problem with some simple query:\n\nselect version();\n\tPostgreSQL 8.3.8 on i686-pc-linux-gnu, compiled by GCC gcc (GCC)\n4.3.2 20081105 (Red Hat 4.3.2-7)\nvacuum full bug_t1;\nvacuum full bug_t2;\nvacuum analyze bug_t1;\nvacuum analyze bug_t2;\nshow default_statistics_target;\n\t1... |
[
{
"msg_contents": "Hi all,\nI have a view v_table defined as following:\n\nselect a,b,c,d,e,f\nfrom t_table\nsort by a,b,c;\n\nthe usage pattern of this view is the following:\n\nselect distinct(a) from v_table;\nselect distinct(b) from v_table where a = \"XXX\";\nselect distinct(c) from v_table where a = \"X... |
[
{
"msg_contents": "All,\n\nI've been looking at pg_stat_user_tables (in 8.3, because of a project I\nhave), and it appears that autovacuum, and only autovaccum, updates the\ndata for this view. This means that one can never have data in\npg_stat_user_tables which is completely up-to-date, and if autovacuum is\... |
[
{
"msg_contents": "Hello,\n\nI am relatively new to postgres (just a few months) so apologies if\nany of you are bearing with me.\n\nI am trying to get a rough idea of the amount of bang for the buck I\nmight see if I put in a connection pooling service into the enviroment\nvs our current methodology of using p... |
[
{
"msg_contents": "Hello all,\n\nI am trying to use aggregate queries in views, and when joining these \nviews to other\ntables, I get seq scan in the view, even if index scan would be clearly \nbetter. The views\nI am using in my Db are actually long pivot queries, but the following \nsimple test case is enoug... |
[
{
"msg_contents": "We have a production database server ... it's quite busy but usually\nworking completely fine, simple queries taking a fraction of a\nmillisecond to run.\n\nRecently we've frequently encountered issues where some simple selects\n(meaning, selects doing an index lookup and fetching one row) ha... |
[
{
"msg_contents": "Sorry for the blast...\nI am running into a POSTGRES error. It appears to be the DBMGR[4289]. Any ideas what the error maybe?\n\n\n[cid:image001.png@01CB549C.48946FF0]",
"msg_date": "Wed, 15 Sep 2010 07:07:35 -0400",
"msg_from": "<Timothy.Noonan@emc.com>",
"msg_from_op": true,
... |
[
{
"msg_contents": "Hi,\n\nI am confronted with a use case where my database mainly does big\naggregate select (ROLAP), a bunch of batch jobs, and quite few OLTP.\n\nI come into cases where the planner under-estimates the number of rows\nin some relations, chooses to go for nested loops, and takes forever to\nco... |
[
{
"msg_contents": "Since I've never stumbled on this until now, and I spend all day looking \nat this sort of thing, I'm guessing many of you haven't seen the \nfollowing collection of 3ware controller trivia either: \nhttp://makarevitch.org/rant/3ware/\n\nAll moving toward obsolete with 3ware being a part of ... |
[
{
"msg_contents": "Hello,\n\nwe are experiencing some performance degradation on a database where\nthe main table is running towards the 100M record. Together with the\nslowness of the queries I notice these symptoms:\n\n- size bloat of partial indexes\n- very bad planning estimates\n\nI'd appreciate any hint t... |
[
{
"msg_contents": "Hi All,\n\n(pg 8.3.7 on RHEL 2.6.18-92.el5 )\n\nI ran the query below (copied from\nhttp://pgsql.tapoueh.org/site/html/news/20080131.bloat.html ) on a\nproduction DB we have and I am looking at some pretty nasty looking\nnumbers for tables in the pg_catalog schema. I have tried a reindex\nan... |
[
{
"msg_contents": "All,\n\nI have a reporter who wants to talk to a data warehousing user of\nPostgreSQL (> 1TB preferred), on the record, about 9.0. Please e-mail\nme if you are available and when good times to chat would be (and time\nzone). Thanks!\n\n-- \n -- Josh Berkus\n... |
[
{
"msg_contents": "The autovacuum daemon currently uses the number of inserted and\nupdated tuples to determine if it should run VACUUM ANALYZE on a\ntable. Why doesn’t it consider deleted tuples as well?\n\nFor example, I have a table which gets initially loaded with several\nmillion records. A batch process ... |
[
{
"msg_contents": "While everybody else was talking about a new software release or \nsomething today, I was busy finally nailing down something elusive that \npops up on this list regularly. A few weeks ago we just had a thread \nnamed \"Performance on new 64bit server compared to my 32bit desktop\" \ndiscuss... |
[
{
"msg_contents": "Hello,\n\nI have received some help from the IRC channel, however, the problem still exists. When running the following query with enable_seqscan set to 0, it takes less than a second, whereas with it set to 1, the query returns in 14 seconds. The machine itself has 8GB Ram and is running Pos... |
[
{
"msg_contents": "I can't tell if you meant for this to be insulting or my reading it that way is wrong, but it certainly wasn't put in a helpful tone. Let me summarize for you. You've been told that putting ORDER BY into a view is a generally poor idea anyway, that it's better to find ways avoid this class ... |
[
{
"msg_contents": "Hello!\n\nI have this table:\n\ncreate table test (\n\ts1 varchar(255),\n\ts2 varchar(255),\n\ti1 integer,\n\ti2 integer,\n\n... over 100 other fields\n\n);\n\ntable contains over 8 million records\n\nthere's these indexes:\n\ncreate index is1 on test (s1);\ncreate index is2 on test (s2);\ncr... |
[
{
"msg_contents": "We've come to a tipping point with one of our database servers, it's\ngenerally quite loaded but up until recently it was handling the load\nwell - but now we're seeing that it struggles to process all the\nselects fast enough. Sometimes we're observing some weird lock-like\nbehaviour (see m... |
[
{
"msg_contents": "Hi all\n\nI've have a strange problem with my Windows postgresql-9.0 service \nstopping after any transaction which manipulates tables in any database \n(Deleting records, Inserting records, bulk importing via \\copy, etc). This \nproblem occurs regardless whether I'm accessing the database s... |
[
{
"msg_contents": "Our Java application manages its own schema. Some of this is from Hibernate,\nbut some is hand-crafted JDBC.\n\nBy way of an upgrade path, we have a few places where we have added\nadditional indexes to optimize performance, and so at startup time the\napplication issues \"CREATE INDEX ...\" ... |
[
{
"msg_contents": "Hi,\n\nCan any one of you suggest how the archived Xlogs can be cleaned in\npostgres-9.\n\nWe want to use streaming replication and have set the \"wal_level\" to\n\"hot_standby\" and \"archive_mode\" to \"on\".\n\nRegards,\nNimesh.\n\nHi,Can any one of you suggest how the archived Xlogs can b... |
[
{
"msg_contents": "I'm doing an OS upgrade and have been sitting on 8.4.3 for sometime. I\nwas wondering if it's better for the short term just to bring things\nto 8.4.4 and let 9.0 bake a bit longer, or are people with large data\nsets running 9.0 in production already?\n\nJust looking for 9.0 feedback (unders... |
[
{
"msg_contents": "Hi,\n\n After reading lots of documentation, I still don't understand fully how\nPG knows if some needed data is in memory or in second storage.\n\n While choosing the best query plan, the optimizer must take this into\naccount. Does PG consider this? If so, how does it know?\n\n I pres... |
[
{
"msg_contents": "Hi,\n\n I have this situation:\n\nDatabase size: 7,6GB (on repository)\nMemory size: 7,7GB\n1 CPU: aprox. 2GHz Xeon\nNumber of tables: 1 (empresa)\n\nCREATE TABLE \"public\".\"empresa\" (\n \"cdempresa\" INTEGER NOT NULL,\n \"razaosocial\" VARCHAR(180),\n \"cnpj\" VARCHAR(14) NOT NULL,\n... |
[
{
"msg_contents": "Hi,\n\nAre there any significant performance improvements or regressions from 8.4 to 9.0? If yes, which areas (inserts, updates, selects, etc) are those in?\n\nIn a related question, is there any public data that compares the performances of various Postgresql versions? \n\nThanks\n\n\n ... |
[
{
"msg_contents": "Hi everyone. I have a question, and it's well beyond me to even speculate\nabout the inner workings of postgresql on this.\n\nI have a \"places\" table, and a \"coordinates\" column, of type POINT.\n\nIf I want to find every place within, for example, a distance of 1 unit from\nan arbitrary p... |
[
{
"msg_contents": "Simon, Greg, etc.,\n\nJust barked my nose against a major performance issue with CE &\npartitioning, and was wondering if anyone had poked at it.\n\nThe issue is this: when a partitioned table is evaluated by the planner\nfor constraint exclusion, it evaluates ALL check constraints on each\np... |
[
{
"msg_contents": "On 3/10/2010 7:39 AM, Richard Troy wrote:\n\n> I can't speak for modern \"OpenVMS\", but \"back in the day\", VMS had a very\n> effective memory management strategy which, in effect, made it as if all\n> memory was a cache for disk. It did this by means of a mechanism by which\n> to identify ... |
[
{
"msg_contents": "Hi,\n\nfor whom it may concern:\nhttp://pdos.csail.mit.edu/mosbench/\n\nThey tested with 8.3.9, i wonder what results 9.0 would give.\n\nBest regards and keep up the good work\n\nHakan\n\nHi,for whom it may concern:http://pdos.csail.mit.edu/mosbench/They tested with 8.3.9, i wonder what resul... |
[
{
"msg_contents": "Hi, \n\nWe have done the following test with PostgreSQL 9.0.\n\ncreate table bytea_demo ( index int, part1 bytea)\");\n\nThen we have instantiated a loop (1000) with the following action: \n\ninsert into bytea_demo ( index, part1, ) values ('%d', '%s'); \n \", i, entry);\n\n1a) In a fir... |
[
{
"msg_contents": "Hi All,\n\nWe have been trying to implement the streaming replication on one of our\ntest servers. We have set archive_xlogs to on. But on the standby server,\nwhen we start the database we get error the following errors:\n\nLOG: shutting down\nLOG: database system is shut down\nLOG: datab... |
[
{
"msg_contents": "All,\n\nThere's a number of blog tests floating around comparing XFS and Ext3,\nand the various Linux schedulers, for PGDATA or for an all-in-one mount.\n\nHowever, the WAL has a rather particular write pattern, and it's\nreasonable to assume that it shouldn't be optimized the same way as\nPG... |
[
{
"msg_contents": "Sorry to forget to give the postgres version as 8.1\n\nOn Thu, Oct 7, 2010 at 2:12 PM, Srikanth K <sreekanthkata@gmail.com> wrote:\n\n> Hi Can u Please let me know how can i optimize this query better. As i am\n> attaching u the Query, Schema and Explain Analyze Report.\n>\n> Plerase help me ... |
[
{
"msg_contents": "currently PG 8.1.3. See attached for my postgresql.conf. Server is\nfreebsd 6.2 w/ a fast 3TB storage array and only 2GB of ram.\n\nWe're running RTG which is a like mrtg, cricket, etc. basically\nqueries network devices via SNMP, throws stats into the DB for making\npretty bandwidth grap... |
[
{
"msg_contents": "I'm weighing options for a new server. In addition to PostgreSQL, this \nmachine will handle some modest Samba and Rsync load.\n\nI will have enough RAM so the virtually all disk-read activity will be \ncached. The average PostgreSQL read activity will be modest - a mix of \nsingle-record and... |
[
{
"msg_contents": "I know that there haven been many discussions on the slowness of count(*) even \nwhen an index is involved because the visibility of the rows has to be \nchecked. In the past I have seen many suggestions about using triggers and \ntables to keep track of counts and while this works fine in a ... |
[
{
"msg_contents": "I have more than 1300000 records in crm table and I partioned the table with\ndeleted = 0 key.\nIt is working fine except that after partioion query is taking more time\nthan the previous one.\nI already set constraint_exclusion = on; My DB version is Postgresql 8.1\n\nI added the explain ana... |
[
{
"msg_contents": "I already sent the mail earlier. but added wrong explain. So I mail it\nagain.\n\nI have more than 1300000 records in crm table and I partioned the table with\ndeleted = 0 key.\nIt is working fine except that after partioion query is taking more time\nthan the previous one.\nI already set con... |
[
{
"msg_contents": "I need to join two tales say TAB_A and TAB_B, where TAB_A is greater than\nTAB_B in size and records.\nWhich Table should I put first in join order?\nAny idea please.\n\nI need to join two tales say TAB_A and TAB_B, where TAB_A is greater than TAB_B in size and records.Which Table should I pu... |
[
{
"msg_contents": "Hello,\nI have heard it said that if a stored procedure is declared as VOLATILE,\nthen no good optimizations can be done on queries within the stored\nprocedure or queries that use the stored procedure (say as the column in a\nview). I have seen this in practice, recommended on the irc channe... |
[
{
"msg_contents": "Are there any performance implications (benefits) to executing queries\nin a transaction where\nSET TRANSACTION READ ONLY;\nhas been executed?\n\n\n-- \nJon\n",
"msg_date": "Tue, 12 Oct 2010 12:24:47 -0500",
"msg_from": "Jon Nelson <jnelson+pgsql@jamponi.net>",
"msg_from_op": true... |
[
{
"msg_contents": "I've got a few tables that periodically get entirely refreshed via a COPY. I\ndon't really have a good mechanism for detecting only rows which have\nchanged so even though the differences are small, a full copy is easiest.\n However, the data includes a primary key column, so I can't simply l... |
[
{
"msg_contents": "Hi, everyone. I'm working with a client to try to optimize their use of\nPostgreSQL. They're running 8.3 on a Windows platform, packaged as part\nof a physical product that is delivered to customers.\n\nWe're planning to upgrade to 9.0 at some point in the coming months, but\nthis question ... |
[
{
"msg_contents": "I hit an issue with window aggregate costing while experimenting with\nproviding a count of the full match along side a limited result set.\nSeems that the window aggregate node doesn't take into account that it\nhas to consume the whole input before outputting the first row. When\nthis is co... |
[
{
"msg_contents": "Hello\n\nI have an application hosted on Heroku. They use postgres. It's more or less\nabstracted away, but I can get some performance data from New Relic. For the\nmost part, performance is ok, but now and then some queries take a few\nseconds, and spike up to 15 or even 16 seconds! Ouch!\n\... |
[
{
"msg_contents": "Hello\n\nI have an application hosted on Heroku. They use postgres. It's more or less\nabstracted away, but I can get some performance data from New Relic. For the\nmost part, performance is ok, but now and then some queries take a few\nseconds, and spike up to 15 or even 16 seconds! Ouch!\n\... |
[
{
"msg_contents": "Hello people,\n\nI'm having trouble to persuade index scan to check all of the conditions \nI specify _inside_ index cond. That is, _some_ condition always get \npushed out of index cond and applied later (which will often result, for \nmy real table contents, in too many unwanted rows initia... |
[
{
"msg_contents": "We are in the process of testing migration of our oracle data warehouse\nover to postgres. A potential showstopper are full table scans on our\nmembers table. We can't function on postgres effectively unless index\nscans are employed. I'm thinking I don't have something set correctly\nin m... |
[
{
"msg_contents": "postgres 8.4.4 on openSUSE 11.3 (2.6.36rc7, x86_64).\n\nI was watching a fairly large query run and observed that the disk\nlight went out. I checked 'top' and postgres was using 100% CPU so I\nstrace'd the running process.\nThis is what I saw:\n\nlseek(87, 0, SEEK_END) = 585... |
[
{
"msg_contents": "Damon Snyder wrote:\n \n> I have heard it said that if a stored procedure is declared as\n> VOLATILE, then no good optimizations can be done on queries within\n> the stored procedure or queries that use the stored procedure (say\n> as the column in a view). I have seen this in practice, reco... |
[
{
"msg_contents": "Hi Guys,\n\nI 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 need for a unique key across a... |
[
{
"msg_contents": "We currently have\n\n log_min_duration_statement = 5000\n\nand are seeing statements like the following logged\n\n2010-10-16 05:55:52 EDT [6334]: [1-1] LOG: duration: 5572.517 ms \nstatement: EXECUTE <unnamed> [PREPARE: COMMIT]\n2010-10-16 06:06:24 EDT [26856]: [1-1] LOG: duration: 5617... |
[
{
"msg_contents": "There was some doubt as for the speed of doing the select count(*) in \nPostgreSQL and Oracle.\nTo that end, I copied the most part of the Oracle table I used before to \nPostgres. Although the copy\nwasn't complete, the resulting table is already significantly larger \nthan the table it was ... |
[
{
"msg_contents": "There was some doubt as for the speed of doing the select count(*) in \nPostgreSQL and Oracle.\nTo that end, I copied the most part of the Oracle table I used before to \nPostgres. Although the copy\nwasn't complete, the resulting table is already significantly larger \nthan the table it was ... |
[
{
"msg_contents": "At present for reporting I use following types of query:\nselect crm.*, crm_cnt.cnt\nfrom crm,\n(select count(*) as cnt from crm) crm_cnt;\nHere count query is used to find the total number of records.\nSame FROM clause is copied in both the part of the query.\nIs there any other good alterna... |
[
{
"msg_contents": "I have a table with an array column.\nI added a GIN index to the array:\n\nCREATE INDEX foo_idx ON t USING GIN (alternatecodes) WHERE\nalternatecodes IS NOT NULL;\n\nThat's all well and good.\nHowever, some queries started failing and I was able to reproduce the\nbehavior in psql!\n\nSELECT *... |
[
{
"msg_contents": "8.4.5\n\nI consistently see HashJoin plans that hash the large table, and scan the small table. This is especially puzzling in some cases where I have 30M rows in the big table and ~ 100 in the small... shouldn't it hash the small table and scan the big one?\n\nHere is one case I saw just re... |
[
{
"msg_contents": "I have the following query running on 8.4, which takes 3516 ms. It is\nvery straight forward. It brings back 116412 records. The explain only\ntakes 1348ms\n\n \n\nselect VehicleUsed.VehicleUsedId as VehicleUsedId , \n\nVehicleUsed.VehicleUsedDisplayPriority as VehicleUsedDisplayPriority ,... |
[
{
"msg_contents": "Folks,\n\nI am running into a problem with the postmaster: from time to time, it\nruns for a long time. E.g., from top:\n\n23425 postgres 20 0 22008 10m 10m R 99.9 0.5 21:45.87 postmaster\n\nI'd like to figure out what it is doing. How can I figure out what\nstatement causes the proble... |
[
{
"msg_contents": "I don't know why seq scan is running on the following query where the same\nquery is giving index scan on other servers:\nexplain analyze\nselect *\nfrom act\nwhere act.acttype in ( 'Meeting','Call','Task');\n QUERY PLAN\n----------------------------------------------------------------------... |
[
{
"msg_contents": "\nHello,\n\nWe are using PostgreSQL for storing data and full-text search indexes\nfor the webiste of a daily newspaper. We are very happy overall with the\nresults, but we have one \"weird\" behaviour that we would like to solve.\n\nThe problem is when we index objects into the full-tex... |
[
{
"msg_contents": "Now that some of my recent writing has gone from NDA protected to public \nsample, I've added a new page to the PostgreSQL wiki that provides a \ngood starting set of resources to learn about an ever popular topic \nhere, how write cache problems can lead to database corruption: \nhttp://wik... |
[
{
"msg_contents": "Hello,\n\nDoes anyone have any experience with running postgreSQL on Blue Arc's \nnetwork storage products? In particular, we are interested in the the \nTitan and Mercury series:\n\nhttp://www.bluearc.com/data-storage-products/titan-3000-network-storage-system.shtml\nhttp://www.bluearc.com/d... |
[
{
"msg_contents": "Rob Wultsch wrote:\n \n> I really would like to work with PG more and this seems like\n> [full_page_writes] would be a significant hindrance for certain\n> usage patterns. Lots of replication does not take place over gig...\n \nCertainly most of the Wisconsin State Courts replication takes p... |
[
{
"msg_contents": "Hello,\n\nWhat is the general view of performance CPU's nowadays when it comes to \nPostgreSQL performance? Which CPU is the better choice, in regards to \nRAM access-times, stream speed, cache synchronization etc. Which is the \nbetter CPU given the limitation of using AMD64 (x86-64)?\n\nWe'... |
[
{
"msg_contents": "Hello Experts,\nMy application uses Oracle DB, and makes use of OCI interface.\nI have been able to develop similar interface using postgreSQL library.\nHowever, I have done some tests but results for PostgreSQL have not been \nencouraging for a few of them.\n\nMy questions/scenarios are:\n\n... |
[
{
"msg_contents": "Hi all, \n\nWe are tuning a PostgreSQL box with AIX 5.3 and got stucked in a very odd situation.\nWhen a query got ran for the second time, the system seems to deliver the results to slow.\n\nHere´s some background info:\n\nAIX Box: \nPostgreSQL 8.4.4, AIX 5.3-9 64bits, SAN IBM DS3400, 8x450G... |
[
{
"msg_contents": "Hi experts,\n\nI have a (near) real-time application in which inserts into the database needs \nto be visible to queries from other threads with minimal delay. The inserts are \ntriggered by real-time events and are therefore asynchronous (i.e. many \nperformance tips I read related to batch ... |
[
{
"msg_contents": "Hey\n\nTurned on log_min_duration_statement today and started getting timings on sql statements (version 8.3.10).\nCan anyone please tell me how to interpret the (S_nn/C_nn) information in the log line.\n\nLOG: duration: 19817.211 ms execute S_73/C_74: ....(statement text) .....\n\nThanks f... |
[
{
"msg_contents": "Which one is faster?\nselect count(*) from talble\nor\nselect count(id) from table\nwhere id is the primary key.\n\nWhich one is faster?select count(*) from talbleorselect count(id) from tablewhere id is the primary key.",
"msg_date": "Tue, 26 Oct 2010 16:56:48 +0600",
"msg_from": "AI... |
[
{
"msg_contents": "Hello,\n\nWhat is the general view of performance CPU's nowadays when it comes to \nPostgreSQL performance? Which CPU is the better choice, in regards to \nRAM access-times, stream speed, cache synchronization etc. Which is the \nbetter CPU given the limitation of using AMD64 (x86-64)?\n\nWe'... |
[
{
"msg_contents": "I have the following query:\n\n \n\nselect distinct Region.RegionShort as RegionShort\n\n,County.County as County \n\nfrom Region \n\njoin PostalCodeRegionCountyCity on\n(PostalCodeRegionCountyCity.RegionId=Region.RegionId) \n\njoin DealerGroupGeoCache on\n(DealerGroupGeoCache.RegionId=Postal... |
[
{
"msg_contents": "CentOS 5.4 and 5.5\n\nQuery\nSELECT sum(usramt) as givensum,\n sum (case when usedid > 0 then usramt else 0 end) as usedsum\n FROM argrades\n WHERE userstatus in (5) and\n membid in (select distinct members.membid from members, cards\nwhere ... |
[
{
"msg_contents": "Hi Steve and other friends,\nSome information you would be interested in:\nI did some further tests using libpq in my code.\nI used a stored proc to insert 100 thousand rows in a table, it took 25 sec \n(almost same as time taken by Oracle PL/SQL and OCI interface).\nSame inserts through lib... |
[
{
"msg_contents": "I have an app which imports a lot of data into a temporary table, does\na number of updates, creates some indexes, and then does a bunch more\nupdates and deletes, and then eventually inserts some of the columns\nfrom the transformed table into a permanent table.\n\nThings were not progressin... |
[
{
"msg_contents": "Hi,\n\nI have a Linux Server (Debian) with Postgres 8.3 and I have problems with a\nmassive update, about 400000 updates/inserts.\nIf I execute about 100000 it seems all ok, but when I execute 400000, I have\nthe same problem with or without a transaction (I need to do with a\ntransaction) in... |
[
{
"msg_contents": "hello --\n\nmy last email was apparently too long to respond to so i'll split it up into shorter pieces. my first question :\n\nmy understanding of how range partitioning and constraint exclusion works leads me to believe that it does not buy any query performance that a clustered index does... |
[
{
"msg_contents": "I've been having trouble with a query.\nThe query is a cross join between two tables.\nInitially, I mis-typed the query, and one of the columns specified in\nthe query doesn't exist, however the query ran nonetheless.\n\nThe actual query:\nselect gid from t2, t3 where t2.name = t3.name and t3... |
[
{
"msg_contents": "Unfortunately I have not received a response on this question. Is more\ninformation needed? Does anyone have any ideas why the estimates may be\nbad? Or what I might be able to do to speed this up?\n\n \n\nthanks\n\n \n\nFrom: Ozer, Pam \nSent: Tuesday, October 26, 2010 4:27 PM\nTo: 'pgsql... |
[
{
"msg_contents": "Hi pgsql-performance,\n\nI was doing mass insertions on my desktop machine and getting at most\n1 MB/s disk writes (apart from occasional bursts of 16MB). Inserting 1\nmillion rows with a single integer (data+index 56 MB total) took over\n2 MINUTES! The only tuning I had done was shared_buffe... |
[
{
"msg_contents": "Hi,\nI am trying to tune my libpq program for insert performance.\nWhen I tried inserting 1M rows into a table with a Primary Key, it took almost \n62 seconds.\nAfter adding a composite index of 2 columns, the performance degrades to 125 \nseconds.\nI am using COPY to insert all data in 1 tra... |
[
{
"msg_contents": "Hello\n\nWe have an application that needs to do bulk reads of ENTIRE Postgres tables very quickly (i.e. select * from table). We have \nobserved that such sequential scans run two orders of magnitude slower than observed raw disk reads (5 MB/s versus 100 MB/s). Part \nof this is due to the... |
[
{
"msg_contents": "Hi\n\nSorry, my previous post haven't shown in this list, so I repost this\none. I have a sql become very slow after upgrade to 8.4.5.\nThe table creation sql like this.\n\nbegin;\nCREATE TABLE t_a (\n id INT NOT NULL PRIMARY KEY\n);\nCREATE TABLE t_b (\n id INT NOT NULL PRIMARY... |
[
{
"msg_contents": "I wrote a little Perl script, intended to test the difference that array \ninsert makes with PostgreSQL. Imagine my surprise when a single record \ninsert into a local database was faster than batches of 100 records. \nHere are the two respective routines:\n\nsub do_ssql\n{\n my $exec_cnt... |
[
{
"msg_contents": "I wrote a little Perl script, intended to test the difference that array \ninsert makes with PostgreSQL. Imagine my surprise when a single record \ninsert into a local database was faster than batches of 100 records. \nHere are the two respective routines:\n\nsub do_ssql\n{\n my $exec_cnt... |
[
{
"msg_contents": "Can you hear me now?\n\n-- \n \nMladen Gogala \nSr. Oracle DBA\n1500 Broadway\nNew York, NY 10036\n(212) 329-5251\nhttp://www.vmsinfo.com \nThe Leader in Integrated Media Intelligence Solutions\n\n\n\n",
"msg_date": "Tue, 02 Nov 2010 17:21:05 -0400",
"msg_from": "Mladen Gogala <mladen... |
[
{
"msg_contents": "I sent 2 emails, both containing a Perl code sample, but none of them \nwent through. Essentially, I was testing Perl array bind & execute. \nEverything went well, except for the fact that array execute is no \nfaster than the row-by-row way of executing things. I was surprised \nbecause I ex... |
[
{
"msg_contents": "Hello\n\nWe have an application that needs to do bulk reads of ENTIRE\nPostgres tables very quickly (i.e. select * from table). We have\nobserved that such sequential scans run two orders of magnitude slower\nthan observed raw disk reads (5 MB/s versus 100 MB/s). Part of this is\ndue to the... |
[
{
"msg_contents": "Where can I find the documentation describing the buffer replacement \npolicy? Are there any parameters governing the page replacement policy?\n\n-- \n \nMladen Gogala \nSr. Oracle DBA\n1500 Broadway\nNew York, NY 10036\n(212) 329-5251\nhttp://www.vmsinfo.com \nThe Leader in Integrated Media ... |
[
{
"msg_contents": "Maciek/Vitalii-\n\nThanks for the pointers to the JDBC work. \n\nLuckily, we had already found the COPY support in the pg driver, but \nwere wondering if anyone had already written the complimentary unpacking \ncode for the raw data returned from the copy.\n\nAgain the spec is clear enough th... |
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