Hi John,

> I'm glad it's not just me! I assume the only answer is to use a high
> degree of locking? Like table_stability or "select * from T with
> lock". Ouch.
>
> Of course you then loose all multi-gen advantages!
>
> Otherwise you just have to *hope* nothing sneaks through the trigger
> below, and to be properly sure, each time you use the table, scan it
> again in your new transaction context to ensure nothing invalid
> exists.
>
> I suppose the whole idea of constraints between records (rather than
> just inside a single record) isn't all that well suited to multi-gen
> databases.
>
> They even had to 'cheat' to get PK's to work!!! ;)
>
> At least I know of this limitation now. I always wondered why people
> like M$ didn't use multi-gen. Now I know...

Ehm... on the other hand... MS SQL is going to implement this in
Yukon (SQL Server 9). And PostgreSQL has it, so does Oracle,
Netfrastructure, Nexus ( I believe ), ThinkSQL, InnoDB (MySQL)
and more...

Guess it's gotta be good for something :-D

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server.
Upscene Productions
http://www.upscene.com