|Subject||Re: [firebird-support] Check constraints vs. user defined triggers|
> On Dec 29, 2014, at 9:56 PM, Aldo Caruso aldo.caruso@... [firebird-support] <email@example.com> wrote:No one has answered, so I'll offer a not-very interesting suggestion.
>Triggers aren't launched like separate programs, but get incorporated in the compiled request so eight small triggers have about the same performance impact as one large trigger.
> I have a table with four check constraints, which basically check
> logical conditions between its fields.
> In order to enforce those constraints, Firebird creates behind the
> scenes two triggers for each one of them (I suppose one for update and
> the other for insert operation). So in this case it ends up with eight
> system created triggers.
> I suppose this degradates performance of massive insert or updates, as
> four triggers have to be launched for each insert or update operation.
>In your situation, I'd build a test and measure the diffence in performance of the two approaches, even though in theory there shouldn't be much.
> Does it have sense in order to enhace performance not to use check
> contraints but instead check those constraints globally using only two
> user defined triggers (before insert and before update), raising
> exceptions when logical conditions aren't met ?
> Is it worthwhile ? Which are the pros and cons of this approach ?