Database Memory Area

SGA

• Data buffer cache - cache data and index blocks for faster access
• Shared pool - cache parsed SQL and PL/SQL statements
• Dictionary Cache - information about data dictionary objects
• Redo Log Buffer -  committed transactions that are not yet written to the redo log files
• JAVA pool - caching parsed Java programs
• Streams pool - cache Oracle Streams objects
• Large pool - used for backups, UGAs, etc

Dynamic Component

• shared pool
• large pool
• java pool
• streams pool
• DEFAULT buffer cache
• KEEP buffer cache
• RECYCLE buffer cache
• DEFAULT 2K buffer cache
• DEFAULT 4K buffer cache
• DEFAULT 8K buffer cache
• DEFAULT 16K buffer cache
• DEFAULT 32K buffer cache
• Shared IO Pool
• ASM Buffer Cache

Tables:

v$sgainfo : v$sga : v$sga_dynamic_components

PGA

Stores data and control information for a single process such as sort area, hash area, session cursor cache

UGA

Holds session-based information. Dedicated server mode stores in PGA and Shared server mode stores in SGA