On 1/31/07, Geoffrey <esoteric@xxxxxxxxxxxx> wrote:
We are trying to track down an issue with our PostgreSQL application. We are running PostgreSQL 7.4.13 on Red Hat Enterprise ES 3. We have a situation where the postgres backend process drops core and dies. We've tracked this to an unusual situation where a sequence value that is being created during the process that is causing the core file generation. The thing that is bizarre is that the sequence value skips 30+ entries. How is this even possible? Any suggestions would be greatly appreciated.
In addition to previous suggestions (rollback/server crashes), perhaps a hint where you can look at. I personally had an experience like this with sequences in Oracle. An default oracle sequence caches 20 records in memory, which caused the unused records to be "gone" on a server reboot, and worse, in case the sequence was "swapped" out of memory because it wasn't used for a while. I don't know if you used the "cache" statement while creating your sequence. But in case you did, this can also explain why you have "missing" sequence records. But you must have explicitly set the cache option, since the default of postgresql is 1 [1], not 20 [2]. Please note, my findings with cache are based on the behavour of Oracle. I didn't test this with postgresql. Regards, Wessel van Norel [1] http://www.postgresql.org/docs/8.1/interactive/sql-createsequence.html [2] http://www.stanford.edu/dept/itss/docs/oracle/10g/server.101/b10759/statements_6014.htm#sthref5342
