Shared Pool (Oracle)

The shared pool (shared memory area in the SGA) is used by Oracle to hold several key memory structures. Most important among these are the data dictionary cache and the shared SQL area.

The data dictionary cache contains information on Oracle objects e.g.

naming

definition

access

It is regularly referenced by Oracle itself, as well as some application programs and database users.

The shared SQL area, also known as a "shared cursor cache", is a memory area which contains the parsed representation of SQL statements. Since a certain amount of system overhead is needed to parse an SQL statement, the ability to reuse statements already in memory can add a significant performance advantage.