Shared Pool tuning is the most important aspect of Oracle shared global area optimization. And by far it is the most neglected area.
Shared Pool is a memory area in Oracle which is in turn a part of Oracle SGA(System Global Area). Shared Pool comprises of different meory Strctures. If shared pool size is not configured Properly , the performance of the database suffers drastically.
Shared Pool consists of
1. Library Cache
2. Dictionary Cache
3. Control Structures.
Library cache inturn comprises of Shared Sql Area, Pl/sql Procedures, Functions, Packages (loaded) and control Structures (Latches and locks).