Re: "xmin" system column

On Thu, Jan 26, 2006 at 05:05:19PM -0500, Eric B. Ridge wrote:
> I really need a way to create a unique identifier at the start of a
> top-level transaction, and be able to use it via triggers and/or
> column default values in that or its subtransactions.

I suppose a sequence is out of the question?  Too easy to get it
wrong?

> Is there some kind of "TopXID" magic variable/function that I haven't
> found in the documentation?

Not in the standard installation, but I think a C function that
returns GetTopTransactionId() should work.  It's trivial to write
and examples have been posted before; search the archives.

--
Michael Fuhr