Search Postgresql Archives

Re: serial increments on failed insert

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Jan 14, 2005 at 04:57:19PM -0800, David Kammer wrote:

> Notice that even though the second insert failed, it still incremented 
> the serial value.  This seems counter intuative to the way that serial 
> should work.  Is this truly a bug, or is there a good work around?

That's correct, documented behaviour. A serial column is mostly just a
sequence in disguise. A sequence is guaranteed to give unique,
increasing values, but in many cases may miss a value (for several
reasons - in this case because once a sequence value is used, it's
used, even if the transaction it was used in is rolled back).

Do you really need that column to increase one at a time? Or just
to increase and be unique?

You could look at the maximum value in the column and use the maximum
value plus one (and be prepared to retry if there's an index on that
column to guarantee uniqueness).

Cheers,
  Steve


---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
      subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your
      message can get through to the mailing list cleanly

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux