An Architect's vision

Here is an attempt to summarize how the PGA_AGGREGATE_TARGET defines the upper limits that Oracle should use for the PGA areas of the processes used to run the database. The value of PGA_AGGREGATE_TARGET determines several internal parameters, among them are _pga_max_size, _smm_max_size and _smm_px_max_size . These internal parameters control the maximum amount of memory that can by used a single process (_pga_max_size ), a serial operation resp. "workarea" (_smm_max_size) and the maximum memory available for the operation of a parallel slave in a parallel operation (_smm_px_max_size). In 10.2 the upper limits are driven by the _smm_max_size which is derived from PGA_AGGREGATE_TARGET and can be larger than 100M if you have a PGA_AGGREGATE_TARGET greater than 1GB (I think _smm_max_size = 10% of PGA_AGGREGATE_TARGET if this is > 1GB). The _pga_max_size is then two times _smm_max_size. column name format a40 column value format 999,999,999 select name, value fro...

V$Recovery_Log List of archived redo log files required for recovery V$Archived_Log List of all archived redo log files for the database V$Recover_File List of datafiles need recovery V$Log_History Which log files already applied to Standby Database

In Oracle's database products, an autonomous transaction is an independent transaction that is initiated by another transaction. Autonomous Transactions are independant transactions that can be called from within another transaction. You can call Autonomous Transaction from within PL/SQL Block using pragma Autonomous_transaction When an autonomous transaction is called, the original transaction (calling transaction) is temporarily suspended. The autonomous transaction must commit or roll back before it returns control to the calling transaction. The easiest way to understand autonomous transactions is to see them in action. To do this, we create a test table and populate it with two rows. Notice that the data is not commited. CREATE TABLE at_test ( id NUMBER NOT NULL, description VARCHAR2(50) NOT NULL ); INSERT INTO at_test (id, description) VALUES (1, 'Description ...

Oracle Clusterware is a portable cluster infrastructure that provides High Availability (HA) to RAC databases and other applications. Oracle Clusterware makes applications highly available by monitoring the health of the applications, by restarting applications on failure, by relocating applications to another cluster node when the currently used node fails or when the application can no longer run in the current node.