On 2/9/11 10:59 AM, Sytze de Boer wrote:
> I have a table called WINHST
> This table has 10 indexes
> The 7th index is on a field called SERNO. Expression is upper(serno)
>
> trcask = the search expression
> Select * From winhst Where serno=trcask Order By invnum Into Table (myfile)
Doesn't match the index expression, so it can't use the index.
> Question 1
> In order to speed the search, should I do the following?
> sele winhst
> set order to 7
> Select * From winhst Where serno=trcask Order By invnum Into Table (myfile)
No.
> Question 2
> Does the "order by" clause slow down the select issue ?
Probably a miniscule amount.
What you really need to do is match the index expression in your where clause:
{{{
select *
from winhst
where trcask = upper(serno)
order by invnum
into table (myfile)
}}}
Also, if you don't need all the fields from winhst, then don't select them.
Also,
you'll want an index on invnum. If the index expression is on upper(invnum),
then
your order by needs to match:
{{{
order by upper(invnum)
}}}
It's been almost a decade since I've dealt with this, so please excuse any bad
information here.
Paul
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