I do basically the same thing for files. Except I md5 a 4 character random string, and the sequence ID just incase I get the same one twice -- as it's never been written in stone that I wouldn't -- not to mention the high number of requests for returning a sequence ID back to the pool on a rollback.
Anyway, you might try using the OID rather than a sequence ID but if you rollback the database commit due to failure of an action externally, shouldn't you be cleaning up that useless external stuff as well? -- Rod Taylor This message represents the official view of the voices in my head ----- Original Message ----- From: "Clark C . Evans" <[EMAIL PROTECTED]> To: "Vadim Mikheev" <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]> Sent: Friday, March 15, 2002 8:54 PM Subject: Re: [HACKERS] [BUGS] Bug #613: Sequence values fall back to previously chec > (userland comment) > > On Fri, Mar 15, 2002 at 01:05:33AM -0800, Vadim Mikheev wrote: > | > But sequences should not be under transaction control. Can you > | > safely rollback a sequence? No! The only way to ensure that would > | ... > | > Placing a restriction on an application that says it must treat the values > | > returned from a sequence as if they might not be committed is absurd. > | > | Why? The fact that you are not able to rollback sequences does not > | necessary mean that you are not required to perform commit to ensure > | permanent storage of changes made to database. > > I use sequences to generate message identifiers for a simple > external-to-database message passing system. I also use > them for file upload identifiers. In both cases, if the > external action (message or file upload) succeeds, I commit; > otherwise I roll-back. I assume that the datbase won't give > me a duplicate sequence... otherwise I'd have to find some > other way go get sequences or I'd have duplicate messages > or non-unique file identifiers. > > With these changes is this assumption no longer valid? If > so, this change will break alot of user programs. > > | And why? Just for convenience of << 1% applications which need > | to use sequences in their own, non-database, external objects? > > I think you may be underestimating the amount of "external resources" > which may be associated with a datbase object. Regardless, may of the > database features in PostgreSQL are there for 1% or less of the > user base... > > Best, > > Clark > > -- > Clark C. Evans Axista, Inc. > http://www.axista.com 800.926.5525 > XCOLLA Collaborative Project Management Software > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED] > ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
