No, the UNION is much much faster! That's what I'm surprised at.

>I don't think UNIONS are fully optimizable, Dave. That might explain it. Try both SQLs with SET OPTIMIZE OFF and see what the differences are.
>
>
>>Address is a table with 400,000 records indexed on Addrnum
>>Cons is a table of 120,000 contacts indexed on CCust
>>Both have tags on DELETED()
>>
>>The query...
>>

SELECT A.* FROM Address A, Cons C ;
>>  WHERE C.CCust = "GREATLA2" ;
>>  AND C.PAddrnum = A.Addrnum ;
>>UNION SELECT A.* FROM Address A, Cons C ;
>>  WHERE C.CCust = "GREATLA2" ;
>>  AND C.Addrnum = A.Addrnum
>>

>>runs about 50 times faster than...
>>

SELECT A.* FROM Address A, Cons C ;
>>   WHERE C.CCust = "GREATLA2" ;
>>   AND (C.Addrnum = A.Addrnum OR C.PAddrnum = A.Addrnum)
>>

>>Both queries show as fully optimized with SYS(3054,1), both return the same result set.
>>Strange uh!