Hello: I have a PostgreSQL 9.0.3 database that has suddenly started exhibiting odd read behavior. The version number is: "PostgreSQL 9.0.3 on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-50), 64-bit" This was compiled from source about a year ago and has been running just fine. The database feeds a very low-volume web site (a few hits per minute). Starting a few days ago we started to see a strange behavior where writing to the database causes massive read operations. For example, I have a table that needs to be updated every night (about 20,000 rows). Using Django ORM, we update them one item at a time. Usually the overall process takes a few minutes; it is now taking hours (like over 15 hours). Running atop, we're seeing Read Disk values in the range of 147.2M/10s and Write Disk values in the range of 16K/10s. Together, the Disk throughput is in the high 90% and frequently hits 100%. When I'm not writing to the database, it becomes quiet without any disk activity. This is a 256 MByte system and atop shows we're not swapping. There's nothing unusual in the PostgreSQL logs. Appreciate any pointers as to how I go about identifying the root cause of this problem. Thanks. --Ray ---------------------------------------------- Ray Cote, President Appropriate Solutions, Inc. We Build Software www.AppropriateSolutions.com 603.924.6079 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
