Re: Use a rule or a transaction

On Tue, Aug 15, 2000 at 01:57:17PM -0400, Madel, Kurt wrote:
> Hello,
> 
> I am creating a web based (using php) class registration database with three
> tables directly effected by the registration process:

[snip]

> My question is, would it be better (faster) to use rules or to use a
> transaction.

How about using triggers?  I have used pl/pgsql triggers in the past to do
similar things.  I was not checking a maximum but definitely was keeping a
reference count.  What you want is a trigger that increments on insert,
decrement on delete, and on update, IF the id changed, decrement the old
one, increment the new one..  I suspect you could also have another trigger,
on update on class, that would abort the transaction if class.size ever
becomes bigger than maxsize..

I can't really comment on performance though.....

> Is there a faster way to do this with rules or a better way to do it
> otherwise.
> 
> TIF,
> Kurt

Hope it helps
Antoine

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