|Oracle® TimesTen In-Memory Database Replication Guide
11g Release 2 (11.2.2)
This preface summarizes the new features of Oracle TimesTen In-Memory Database release 11.2.2 that are documented in this guide. It provides links to more information.
You can disable commit dependencies for automatic parallel replication for an active standby pair that uses asynchronous replication and does not contain cache groups. This provides parallel replication over multiple threads that automatically enforces transactional dependencies, but does not enforce transactions to be committed in the same order on the subscriber database as on the master database. For more information, see "Configuring automatic parallel replication with disabled commit dependencies."
DDLReplicationAction connection attributes control what objects that are created or dropped by DDL statements are automatically replicated to the databases involved in an active standby pair replication scheme. For this release, a new level of 3 (not the default) for the
DDLReplicationLevel connection attribute adds replication of the
CREATE VIEW or
DROP VIEW statements, the
CREATE SEQUENCE or
DROP SEQUENCE statements, and the result of running the
ttCacheUidPwdSet built-in procedure to set the cache administration user name and password. When
DDLReplicationLevel=3 and the
DDLReplicationAction connection attribute is set to
INCLUDE, then any new sequences created are included in the replication scheme. See "Controlling replication of objects to all databases in an active standby pair" for details.
When using Oracle Clusterware, you must execute the new
ttCWAdmin -reauthenticate command after modifying any user name or password to enable Oracle Clusterware to store these new user names and passwords. For full details, see "Changing user names or passwords when using Oracle Clusterware".
When you use
ALTER TABLE to add or drop columns, extraneous space or partitions could be added, which can hinder the performance of replication. If you are using relaxed replication, you can eliminate the extraneous space and partitions with
ttMigrate -relaxedUpgrade. For details, see "Column definition options for replicated tables".
There is a new command, the
-logAnalyze command, in the
ttXactLog utility that analyzes the replication logs to measure how much is left to replicate from the active to a standby master and any subscribers and if the current configuration distributes the load appropriately for parallel replication. For more details, see "Analyze outstanding transactions in the replication log".
You can now specify an alias or the IP address of the network interface when you want to use a specific local or remote network interface over which database duplication occurs. For details, see "Duplicating a database".
By default, replication is performed with a single thread. You can increase your performance by configuring parallel replication, which configures multiple threads for sending updates from the source database to the target database and for applying the updates on the target database. For more information, see "Configuring parallel replication".
You have additional control over TimesTen application behavior when Oracle Clusterware is managing a TimesTen active standby pair. The
AppUptimeThreshold Clusterware attributes are new. See "Implementing application failover".
Durable commit behavior has changed. See "DURABLE COMMIT".
LOB columns can be replicated. See "Table requirements for active standby pairs" and "Table requirements and restrictions for classic replication schemes".
TimesTen provides in-memory columnar compression. However, you cannot replicate tables with compressed columns. This restriction is mentioned in "Table requirements for active standby pairs" and "Table requirements and restrictions for classic replication schemes".