Re: 2PC transaction id

Oliver Jowett wrote:
> Tom Lane wrote:
> 
>>It's the TM's responsibility to deal with that.  I would expect it to
>>hand out transaction IDs that consist of a common prefix and a
>>per-database suffix, if it does not know which resources it's dealing
>>with might share a common GID namespace.

> I don't know if we can reasonably expect TMs not to hand out an
> identical XID to different RMs in the same global transaction.

Hm, I suppose we *can* assume that a TM won't hand out the same XID to
the same RM twice (except for the special case of TMJOIN), so we could
append a per-database suffix in the RM itself (e.g. JDBC driver) to
avoid conflicts within a database cluster.

-O