Andrew Sullivan wrote:

>On Wed, May 11, 2005 at 12:36:44PM +0300, Hannu Krosing wrote:
>  
>
>>Why does slony use its own transaction id type (xxid) in the first
>>place, why can't we just use standard xid ?
>>    
>>
>
>I believe it has to do with comparison operators; they didn't exist
>in the way Jan wanted, and he didn't want to create new (and
>potentially-future-conflicting) operators there.
>
>A
>  
>
More pointedly, the comparison operators didn't exist in PG 7.3, so it
was necessary to create something that would function there.

There was no "standard" xid to be used there, as there were no visible
operators in 7.3.