Re: [SQL] transaction processing after error in statement

[Rajesh Kumar Mallah]

Rod Taylor wrote: be recovered either. When committing a transaction the effects of all operations that did not fail will be made permanent. This is how transaction processing is described in the literature. I would be interested in reading that (URLs please) as I didn't see anything in the spec that was interesting on this topic. 4.8.5 from Framework (part 01) An SQL-transaction (transaction) is a sequence of executions of SQL-statements that is atomic with respect to recovery. That is to say: either the execution result is completely successful, or it has no effect on any SQL-schemas or SQL-data. Although i am not aware of the roots of this discussion but would like to comment at this point . When we work with sequences an aborted transaction does have a permanent effect on the last value  of sequence. Is this behaviour not a violation of above defination of transaction ? Regds Mallah. The "execution result is completely successful" could certainly be used to back up PostgreSQLs choice to force a rollback. However, it doesn't differentiate between execution of what the user requested, and execution of recovery procedures on the successful user elements. Irregardless, I wish a commit on a failed transaction would throw an error -- END is good enough for Rollback or Commit. For PostgreSQL to implement this we need Savepoints or nested transactions internally since in many cases data is physically written in order to perform things like Foreign Key constraint checks. ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html