faster alternative to where clause in SQL

Hi

Analytical Views have constraint filters that filter data before pulling the data up , The same happens with input parameters ( place holders) that filter data before pulling the data up .

Select A, B , C from tableA where A='constant' does the same function except its filters the data after its fetched , so its inefficient .

What is the SQL statement ( or CE script statement ) that places filters before pulling the data .

Rishi