RE: accessing the records in a history file

[jpcarr@xxxxxxxxxxxx]

I don't think you want to build an EVI using a column that has thousands of
unique values (like the Date field)

It is better served with a limited number of unique values (Like State
Codes, department numbers)  and that new unique values  are not  "Added to
and removed by the ton)  .

I don't think it would be wise to do them over DATE  & TIME.

Make sure you have a good old fashioned index (ie LF)  by Date.

If most of your reports are for a time period FIRST then sorted by Customer
within that group,  Your existing LF's are backwards.     (They should by
Date/Cust)


John Carr

------------------------------------------
Encoded Vector Indexes are great for enhancing the performance of adhoc
queries against large files.  Not sure if this fits your situation exactly,
but I would do one over DATE, one over TIME and one over Customer ID.
Obviously, if you always know what criteria and sorting you are going to
do, a regular logical would work just as well.  But if you have this large
of a file, you need to have some permanent access paths over it that will
make accessing the records you want faster.  This will help regardless of
whether you use OPNQRYF or SQL.

Dave

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