--- In ib-support@y..., Svein Erling Tysvær

> The only general advice I've gathered, is that you want your

indexes to not

> contain too many duplicate values (e.g. if you index a field named

country,

> you could have an awful lot of persons living in China), then add

the PK at

> the end of that index. I think the reason is that deletes (and

possibly

> inserts) slow down with many duplicates.

Yes, it's my experience, too.

> One thing I suddenly realised: Your PK is (Work_Day, Emp_No). That

means

> that IB has to look up every individual date (since you use BETWEEN

and is

> interested in more than one date) and then try to find the

employee. If

> your PK was the other way around (Emp_No, Work_Day), then IB could

just

> locate the employee once find the first work_day and then traverse

down the

> work_days (since they would be in sequence). I think that would be

worth a

> try.
>
> HTH,
> Set

OK, it could be right, I'll check it.

Thanks for your tips.
Richard