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New Features

This appendix briefly describes the new replication features of the Oracle8 Server and provides pointers to other chapters in this document where you can get additional information.

New features include:

Performance Enhancements

Oracle8 provides significant performance improvements based on the following new features.

Parallel Propagation of Deferred Transactions

Dramatically improves throughput performance by parallelizing the propagation of a replication transaction stream while maintaining consistency and transaction dependencies.

Additional Information: See "Deciding between Serial and Parallel Propagation" on page 3-11.

Internalized Replication Triggers

Internal triggers

improve response time performance
reduce processing overhead
require less administration

Additional Information: See "Oracle's Advanced Replication Architecture" on page 1-19.

Reduced Data Propagation

Oracle8 reduces the amount of replicated data propagated over the network. Propagation can be reduced to only the following: new values of columns updated; old values of columns needed for conflict detection and resolution; and primary key values. This feature is important for performance when replicating LOBs.

Additional Information: See "Minimizing Data Propagation" on page 7-30.

Data Subsetting Based on Subqueries

Snapshots defined with certain types of subqueries can now be fast refreshed. This enables subsets of data to be easily defined and maintained. This feature is important for mass deployment applications, such as salesforce automation and branch automation.

Additional Information: See "Creating Snapshots with Subqueries" on page 2-16.

Large Object Datatypes (LOBs) Support

Oracle8 supports the replication of the following types of large objects:

binary LOBs (BLOBs)
character LOBs (CLOBs)
national language support character LOBs (NCLOBs)

Additional Information: See the following sections: "Datatype Considerations for Replicated Tables" on page 3-21, "Datatype Considerations for Snapshots" on page 4-19.

Improved Management and Ease of Use

Oracle8 facilitates database management with the following features.

Fine grained Quiesce

Replication master groups can now be individually quiesced without impacting other replication groups. Master groups can continue to replication updates while other master groups are quiesced.

Additional Information: See "Suspending Replication Activity for a Master Group" on page 3-18.

Primary Key Snapshots

Primary key snapshots allow you to reorganize master tables while preserving fast refresh capability. Oracle8 adds primary key snapshots as the default, and continues to support ROWID snapshots.

Additional Information: See "Creating Simple Snapshots" on page 2-11 and Chapter B, "Migration and Compatibility".

Snapshot Registration at Master Sites

Oracle8 automatically registers information about a snapshot s at master sites. This facilitates monitoring and distributed administration.

Additional Information: See "Registering a Snapshot at its Master Site" on page 2-35.

Reorganizing Tables With Capability of Fast Refresh

Oracle8 provides utilities to enable you to "reorg" master tables while preserving the consistency of master snapshot logs.

Additional Information: See "Master Table Reorganization and ROWID Snapshots" on page 2-44.

Support for Offline Instantiation

Offline instantiation of schemas and database using Export/Import is now more automatic.

Additional Information: See "Snapshot Cloning and Offline Instantiation" on page 7-15.

Deferred Constraints for Updatable Snapshots

Updatable snapshots now support declarative referential and uniqueness constraints.

Additional Information: See "Managing Snapshots" on page 4-18.

Validate Procedure

A new procedure validates the correctness of multiple master environments to help avoid errors.

Additional Information: See "Validating a Master Group" on page 3-31.

Partitioned Tables and Indexes

Oracle8 supports the replication of partitioned tables and indexes. You can use this feature if you want the replicated table to have the same partitions as the table at the master definition site.

Additional Information: See "Partitioned Tables and Indexes" on page 6-20.

Enhanced, System-Based Security Model

Oracle8 system-based security model:

improves consistency: a single system-level model operates the same in both synchronous and asynchronous environments
improves reliability: transactions are less likely to fail due to the lack of privileges at the receiving sites
simplifies links: a single user can act as repadmin and repsys
eliminates the need for a "user-level" model
one or more snapshot owners can perform snapshot refresh

Additional Information: See "Preparing for Multimaster Replication" on page 3-4, "Preparing for Snapshot Site Replication" on page 4-5, and Appendix B, "Migration and Compatibility".

New Replication Manager Features

Replication Manager now includes several wizards to help you configure your system quickly.

setup of multimaster configurations, including account, schema, and link creation
setup of snapshot site configurations, including account, schema, and link creation
setup of snapshot groups
setup of snapshots

Oracle Replication Manager includes support for most new features of Oracle8 Server replication functionality, including:

automatic recognition of each site's database version and dynamic configuration to manage both 8.x and 7.3 databases
support for managing snapshot logs
easy entry of date and interval expressions for jobs, refresh groups, and scheduled links
for Oracle8 databases, a flag to indicate that a table requires regeneration of replication support
support for registering a site's replication administrator and propagator
a database objects folder to display database objects for master groups
drag and drop functionality for master groups and snapshot refresh groups
support for the validation of a master group at all master sites

A New Features