Opinions may vary, but mine is:
1) remove the GO TOP (the default is ALL)
2) stick with LOCATE
3) stick with single independent indexes (at least for this case)

Your defined TAGs let Rushmore operate nicely for what you describe.

cheers

>in my project, I used LOCATE instead of SEEK:
>
>

>SELECT supp
>   GO top
>   LOCATE FOR code_id=vinv.code_id AND currency=vinv.currency
>

>
>now I'm thinking of changing to SEEK, what's the code, and will it make any difference?
>
>I have index for code_id and currency, should I do the compound index (code_id+currency) as well?
>
>thanks for the help.
>
>regards,
>
>Jerry