Grouper Developers Forum

[Jim Fox <>]

Yes, your right.

Jim


On Wed, 30 Mar 2011, Chris Hyzer wrote:

> Date: Wed, 30 Mar 2011 09:20:42 -0700
> From: Chris Hyzer 
> <>
> To: Jim Fox 
> <>,
>  Shilen Patel 
> <>
> Cc: Grouper Dev 
> <>
> Subject: RE: [grouper-dev] search and sort columns on member table
>
> > > I believe indexes on the sort columns should help in some cases.  For
> > > instance, if you're sorting and paging at the same time.  Though if we find
> > > out that the benefit is small and folks would rather save the database space,
> > > we can leave them off.
> >
> > My thinking is that paging results in sorts of a only few hundred records.
>
> Yeah, but it needs to sort all the records and take a page of them, so an 
> index would help there...  right?
>
> In other words, if the records are:
>
> R, F, Q, J, M, T, X
>
> And you want the second page of size two, then if it is indexed, then it 
> knows the order is:
>
> F, J, M, Q, R, T, X
>
> And if it knows that, then all it has to do is know the size (7), and the 
> second page of size two is records index 2 and 3 (starting at 0).
>
> If it doesn't know the order, then it needs to order them and do the same 
> thing, which is harder.
>
> Thanks,
> Chris