>Hi everybody,
>
>How can I randomly select n (110) codes from some huge table, so these codes would be unique? I'm trying to create a test case now...

Every suggestion you've been given will involve moving through more records than you need. The rand() function will be a performance hit if its used in a SQL. There is a method I learned years ago called a fixed interval random start sample.

If you have 1,000,000 records and you want 110 records, you divide 1M by 110 yielding 9090. You then pick a random number between 1 and 9090 and then you select records from that random start by skipping forward 9090 records per jump.

Using a loop, you get the records so fast your head will spin.

lnTotal = 110
lnInterval = int(1000000 / m.lnTotal)
lnFirst = int(RAND()* m.lnInterval)
lnRec = m.lnFirst
go m.lnRec
for lnCount = 1 to m.lnTotal
?recno()
skip m.lnInterval
endfor

This technique was used to select people for telephone interviews from a list of 13 million numbers. Every query we tried took too much time as they involved some kind of calculation against each record in the table.

The system was much more complex. Certain area codes were deemed less likely to participate, so we had a factor which increased the number of records per area code.

Records that were selected were ineligible to be selected again until after it was used in an interview, etc etc.