Subject | Re: [ib-support] large deletions |
---|---|
Author | Raul Chirea |
Post date | 2002-07-03T23:54:06Z |
____
Hi _/\/ando,
From: "Nando Dessena" <nandod@...>
are distributed aprox. equally the index it's just a waste of space, but
more dispropotion between the two values is, more spped you'll get selecting
the minoritar ones - in our case those with "ACTIVE" = 'Y' (if you don't
believe me, try it ! In fact, thats why some RDBMS's offer a feature named
"partitioned tables", which is an enhaced version of what I've just told
you).
Best regards !
Raul.
(They still sell FoxPro, I've heard !)
Hi _/\/ando,
From: "Nando Dessena" <nandod@...>
> I fully agree with Helen here, and I have to add that an atomic index onIt depends how the values of that column are distributed: if the two values
> a two-value column in a multi-million record table does not look exactly
> a speed enhancer to me.
are distributed aprox. equally the index it's just a waste of space, but
more dispropotion between the two values is, more spped you'll get selecting
the minoritar ones - in our case those with "ACTIVE" = 'Y' (if you don't
believe me, try it ! In fact, thats why some RDBMS's offer a feature named
"partitioned tables", which is an enhaced version of what I've just told
you).
Best regards !
Raul.
(They still sell FoxPro, I've heard !)