|Oracle® Database Administrator's Guide
11g Release 2 (11.2)
|PDF · Mobi · ePub|
Deferred segment creation for partitioned objects
Deferred segment creation now applies to partitioned objects as well as nonpartitioned objects.
You can drop segments from empty tables that were migrated from previous releases, using the
STORAGE clause of the
TRUNCATE statement enables you to deallocate segments for a table.
See "Using TRUNCATE".
You can materialize segments for tables, partitions, and dependent objects for which segment creation was deferred, using the
New default first extent size for partitioned tables improves performance
The default size of the first extent of any new segment for a partitioned table is now 8 MB instead of 64 KB. This helps improve performance of inserts and queries on partitioned tables. Although partitioned tables will start with a larger initial size, once sufficient data is inserted, the space consumption will be the same as in previous releases. You can override this default by setting the
INITIAL size in the storage clause for the table. This new default only applies to table partitions and LOB partitions.
New initialization parameter to improve the performance of
NOLOGGING direct-path inserts
You can now significantly improve the performance of unrecoverable direct path inserts by disabling the periodic update of the control files. You do so by setting the new initialization parameter
FALSE. However, if you perform an unrecoverable direct path insert with these control file updates disabled, you will no longer be able to accurately query the database to determine if any datafiles are currently unrecoverable.
Improved e-mail notification capabilities in Oracle Scheduler
Oracle Scheduler e-mail notification preferences now include options to specify authentication and SSL or TLS protocols for the designated SMTP Server.
Edition attributes of database services
You can set the edition attribute of a database service when you create the service, or you can modify an existing database service to set its edition attribute.
Enhancements to Oracle Database Resource Manager
You can optimize the performance of parallel statements by limiting the parallel statement activity per consumer group, prioritizing parallel statements in the parallel statement queue, and limiting the wait time for parallel statement in the parallel statement queue.
Parallel statement queuing enables efficient management of parallel statements when the database does not have sufficient resources to run a statement at the specified degree of parallelism. A submitted parallel statement is added to the parallel statement queue if the resources required to run the statement exceed the parallel statement activity limit specified for the database or the consumer group to which the parallel statement is assigned. Parallel statement queuing can also manage multiple parallel statement workloads according to the priorities and resource allocations specified by a resource plan.
You can track CPU utilization using per-minute metrics for each resource plan. You can also monitor resource utilization for consumer groups, even if Resource Manager is not enabled, thus allowing you to view the potential effect of Resource Manager.