Re: [GENERAL] Commit problem in read-commited isolation level
On 08/16/2013 10:38 PM, S H wrote: 1) What is your exact Postgres version i.e 8.1.5.? V - 8.1.18 3) You also say it works fine in two environments, but not one. What are the environments? OS and version, memory, Postgres versions, etc. It is working on most of the production system ( more than 100) but failed once in one of the system ( not always). Not sure I understand failed once, not always. Not always would seem to mean it failed more than once. Could you elaborate? Always the same machine or does that change? If the same machine, is there something different about it? OS and version, memory, Postgres versions, etc. RHEL 5.2 , 32 GB , 8.1.18 All the systems are exactly the same? You say at the top the new value is 0, but show 5 as the new value at the bottom. Sorry it is returning new value ie 0 after some time. Corrected the above description. So the commit happens, it just takes time. First guess would be some sort of disk I/O contention problem. Honestly though there is not enough information available to do more than guess. We would need a clearer picture of what happens during these periods before it would be possible to formulate a clearer answer. In other words log information from Postgres, the application and the OS and ideally load information from the system. Also are you talking about a specific procedure that causes this, or seemingly random event? Basically, at this point it would be better to provide as much information as possible. -- Adrian Klaver adrian.kla...@gmail.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Commit problem in read-commited isolation level
On 08/15/2013 10:45 PM, S H wrote: Any triggers on the table? There are no trigger associated with this table. FYI 8.1 is no longer supported. I understand that. If there are some known related issues, it will be easy to convince, Product mgmt team to upgrade the version of postgresql. Are there known issues related to commit problem in 8.1 version. Could be, there where 24 releases over five years. Just not sure at this point you actually are facing a commit problem and more information is needed in any case. 1) What is your exact Postgres version i.e 8.1.5.? 2) In your original post you had this sequence: Current value in colname = 5; Update tablename set colname = 0 where key = 18; commit , in parallel to above queries ( either vacuum or reindex of table was running) After 10 sec following query is executed. select colname from tablename where key = 18 ;it is returning old value i.e colname = 5. After another few seconds select colname from tablename where key = 18 ;it is returning new value i.e colname = 5. You say at the top the new value is 0, but show 5 as the new value at the bottom. Which is correct? 3) You also say it works fine in two environments, but not one. What are the environments? OS and version, memory, Postgres versions, etc. Date: Wed, 7 Aug 2013 17:05:59 -0700 From: adrian.kla...@gmail.com To: msq...@live.com CC: pgsql-general@postgresql.org Subject: Re: [GENERAL] Commit problem in read-commited isolation level On 08/07/2013 04:54 PM, S H wrote: Hi, I have faced very strange problem in one of psotgresql query in one of the production environment. It is working fine in development and other environment. Current value in colname = 5; Update tablename set colname = 0 where key = 18; commit , in parallel to above queries ( either vacuum or reindex of table was running) After 10 sec following query is executed. select colname from tablename where key = 18 ; it is returning old value i.e colname = 5. After another few seconds select colname from tablename where key = 18 ; it is returning new value i.e colname = 5. I thought the new value is 0? Isolevel level is readcommited. Is there any possibility of bug in commit in V8.1 leading to delay of commit ? Any triggers on the table? FYI 8.1 is no longer supported. I need to provide explanation of above behavior to my customer. Regards, -- Adrian Klaver adrian.kla...@gmail.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general -- Adrian Klaver adrian.kla...@gmail.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
Re: [GENERAL] Commit problem in read-commited isolation level
1) What is your exact Postgres version i.e 8.1.5.? V - 8.1.18 3) You also say it works fine in two environments, but not one. What are the environments? OS and version, memory, Postgres versions, etc. It is working on most of the production system ( more than 100) but failed once in one of the system ( not always). OS and version, memory, Postgres versions, etc.RHEL 5.2 , 32 GB , 8.1.18 Current value in colname = 5; Update tablename set colname = 0 where key = 18; commit , in parallel to above queries ( either vacuum or reindex of table was running) After 10 sec following query is executed. select colname from tablename where key = 18 ;it is returning old value i.e colname = 5. After another few seconds select colname from tablename where key = 18 ;it is returning new value i.e colname = 0. You say at the top the new value is 0, but show 5 as the new value at the bottom. Sorry it is returning new value ie 0 after some time. Corrected the above description.
Re: [GENERAL] Commit problem in read-commited isolation level
Any triggers on the table? There are no trigger associated with this table. FYI 8.1 is no longer supported. I understand that. If there are some known related issues, it will be easy to convince, Product mgmt team to upgrade the version of postgresql. Are there known issues related to commit problem in 8.1 version. Date: Wed, 7 Aug 2013 17:05:59 -0700 From: adrian.kla...@gmail.com To: msq...@live.com CC: pgsql-general@postgresql.org Subject: Re: [GENERAL] Commit problem in read-commited isolation level On 08/07/2013 04:54 PM, S H wrote: Hi, I have faced very strange problem in one of psotgresql query in one of the production environment. It is working fine in development and other environment. Current value in colname = 5; Update tablename set colname = 0 where key = 18; commit , in parallel to above queries ( either vacuum or reindex of table was running) After 10 sec following query is executed. select colname from tablename where key = 18 ; it is returning old value i.e colname = 5. After another few seconds select colname from tablename where key = 18 ; it is returning new value i.e colname = 5. I thought the new value is 0? Isolevel level is readcommited. Is there any possibility of bug in commit in V8.1 leading to delay of commit ? Any triggers on the table? FYI 8.1 is no longer supported. I need to provide explanation of above behavior to my customer. Regards, -- Adrian Klaver adrian.kla...@gmail.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
[GENERAL] Commit problem in read-commited isolation level
Hi, I have faced very strange problem in one of psotgresql query in one of the production environment. It is working fine in development and other environment. Current value in colname = 5;Update tablename set colname = 0 where key = 18;commit , in parallel to above queries ( either vacuum or reindex of table was running) After 10 sec following query is executed. select colname from tablename where key = 18 ;it is returning old value i.e colname = 5. After another few seconds select colname from tablename where key = 18 ;it is returning new value i.e colname = 5. Isolevel level is readcommited.Is there any possibility of bug in commit in V8.1 leading to delay of commit ? I need to provide explanation of above behavior to my customer. Regards,
Re: [GENERAL] Commit problem in read-commited isolation level
On 08/07/2013 04:54 PM, S H wrote: Hi, I have faced very strange problem in one of psotgresql query in one of the production environment. It is working fine in development and other environment. Current value in colname = 5; Update tablename set colname = 0 where key = 18; commit , in parallel to above queries ( either vacuum or reindex of table was running) After 10 sec following query is executed. select colname from tablename where key = 18 ; it is returning old value i.e colname = 5. After another few seconds select colname from tablename where key = 18 ; it is returning new value i.e colname = 5. I thought the new value is 0? Isolevel level is readcommited. Is there any possibility of bug in commit in V8.1 leading to delay of commit ? Any triggers on the table? FYI 8.1 is no longer supported. I need to provide explanation of above behavior to my customer. Regards, -- Adrian Klaver adrian.kla...@gmail.com -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
