Question

Consider the following MySQL statement

SELECT AccountNumber, Currency, Balance 
FROM clients 
    JOIN balances ON clients.AccountNumber= balances.AccountNumber  
WHERE date > “2009-01-01”

The query runs slowly, please describe what you would do in attempt to resolve this.

Answer 1

Try this:

SELECT C.AccountNumber, C.Currency, B.Balance FROM clients C INNER JOIN balances B ON C.AccountNumber=B.AccountNumber WHERE C.date > “2009-01-01”

(I assumes: Balance field from table Balances)