SQL Index

[Renier2]

I have the following query, but it runs a bit slow as the table consist of about 30 000 records, i want to know on which columns i must create what type of index to maximize the query?

select r_curcode, r_curdesc, to_char(r_sellrate,'999990.0000') as sellrate, to_char(r_buyrate,'999990.0000') as buyrate, to_char(r_buyairmail,'999990.0000') as buyairmail, to_char(r_buysurfmail,'999990.0000') as buysurfmail from someTable order by datesubmitted, timesubmitted desc limit 3

 

[woogoo]

Well I'd be inclined to put a Compound Index on DateSubmitted and TimeSubmitted.

CREATE INDEX Index_Name ON Table_Name (DateSubmitted, TimeSubmitted)

Then run your query through EXPLAIN and see the results (I think you may be surprised at them), if its not what you'd expect then create two indicies one for each column.

HTH