Re: notify clients on database updates

Daniel Morgan <damorgan_at_x.washington.edu> wrote in news:1067014454.263734 @yasure:

> Triggers in Oracle are atomic just like the rest of the code. It does
> not work like SQL Server
> where they are all independent. So ignore whether the trigger fires ...
> it is irrelevant. If the
> code or procedure commits the actions of the trigger are commited. If
> they rollback they
> rollback the trigger's actions too.
>

Understood.

The problem is with any actions the trigger might take which aren't part of the transaction context, for example writing a message out to a pipe.

If I do it that way, then the problem is that a message reader could see the messages regarding transactions that haven't happened yet (not committed) or could see messages about changes that never take place (because the transaction gets rolled back)

So, if there's no way to delay the trigger til the transaction is committed, then I shall have to go the way of writing messages to an alternate table.

Not a big deal, just means that I have to continuously be polling this notification table, rather than simply block on a read from a pipe. Received on Fri Oct 24 2003 - 12:28:16 CDT