Hi I have few questions from Java stored Procedure and PreparedStatemnt .
As we know whenever executing some query in Java(JDBC) code, there four steps are involved : 1.parse the incoming SQL query 2.compile the query 3.plan/optimize the data acquisition path 4.execute the query
While using PreparedStatement, first time thes all steps gets executed. But, the 4th steps gets executed from next time onwards; and hence it is faster.
Q1) But, what happens in case of StoredProcedure which we call by using CallableStatement ? Are these four steps involved in CallableStatement also ? Whether, similar to PreparedStatement, only the 4th step gets executed from second time onwards?
Q2) Performancewise, which one we can judge as faster ?
Is it the right criteria to select either PreparedStement or CallableStatement (StoreProcedure) (?):-> When the query is simple, use PreparedStatement; and when the query is complex (doing multiple operations in one go) use StoredProcedure ().
Q3) Do these both (PreparedStatement & StoredProcedure) gets stored ins DataBase side ; or in Java. I believe there is no any place in Java to get it stored. So is it stored in DataBase or in any WebServer (if it is running on webserver) ?
I would highly appreciate if any one can help to clearly understand the practical use and difference in StoredProcesure and PreparedStatement.
1) CallableStatement extends PreparedStatement. So yes, the same steps occur. The difference being that "the query" is the call to the stored procedure rather than the actual SQL statement. Rendering step 3 trivial - "run the stored proc" is the plan. 2) It depends on what the CallableStatement does. If it is one statement that is the same as the one the PreparedStatement, the performance should be comparable. If the CallableStatement would have required multiple PreparedStatements, it will be faster as you will save on network traffic. However, you should not start out choosing based on performance. You should choose a design and then only change once you have a proven performance problem. It is often only a small portion of the application that is a bottleneck. I think having maintainable code is more important than trying to pigeonhole the code into a situation it doesn't fit. 3) A PreparedStatement is stored in memory (database driver). the database also stores some recent execution plans but this isn't the one people talk about when they say PreparedStatements are cached.