Oracle: MEMORY MANAGEMENT

MEMORY MANAGEMENT
9. What is SGA ? How it is different from Ver 6.0 and Ver 7.0 ?
The System Global Area in a Oracle database is the area in memory to facilitates the transfer of information between users. It holds the most recently requested structural information between users. It holds the most recently requested structural information about the database. The structure is Database buffers, Dictionary cache, Redo Log Buffer and Shared SQL pool (ver 7.0 only) area.
10. What is a Shared SQL pool ?
The data dictionary cache is stored in an area in SGA called the Shared SQL Pool. This will allow sharing of parsed SQL statements among concurrent users.
11. What is mean by Program Global Area (PGA) ?
It is area in memory that is used by a Single Oracle User Process.
12. What is a data segment ?
Data segment are the physical areas within a database block in which the data associated with tables and clusters are stored.
13. What are the factors causing the reparsing of SQL statements in SGA?
Due to insufficient Shared SQL pool size.
Monitor the ratio of the reloads takes place while executing SQL statements. If the ratio is greater than 1 then increase the SHARED_POOL_SIZE.