Because SQL is so flexible, you can get the same result with two different statements, but one statement might be less efficient. A third cause of poor performance is unnecessary parsing and binding. Recall that before executing a SQL statement, Oracle must parse and bind it. Parsing means examining the SQL statement to make sure it follows syntax rules and refers to valid database objects. Binding means associating host variables in the SQL statement with their addresses so that Oracle can read or write their values.
Many applications manage cursors poorly.
This results in unnecessary parsing and binding, which adds noticeably to processing overhead. If you are unhappy with the performance of your precompiled programs, there are several ways you can reduce overhead. Using Host Arrays Host arrays can increase performance because they let you manipulate an entire collection of data with a single SQL statement. In that row, the SAL column has the value of salary . However, if salary is a host array of size 300, Oracle inserts all 300 rows into the EMP table at once.