How Num field is defined? If it's integer field, you may try BINTOC function instead of STR. Also make sure to get SP1 for VFP9. You may also try to use STR(num, 7) if, say, your Num is Numeric (7,0).

>hi all,
>
>my mstr table have more than 20000 records, every time i run this code under mean increase table mstr,
>this code take more one minute , is there any thing i must modify to make it faster.
>

>insert INTO mstr ;
> Select * From main2 Where ;
>  DtoS(file_date) + DtoS(intervdate)+Str(num) Not In ;
>   (Select  DtoS(file_date) + DtoS(intervdate)+Str(num) ;
>    From mstr)
>

>thanks