Summary of four new minor features of Oracle 11g R2

BKJIA featured translations] in the previous articles, BKJIA briefly described several new features of Oracle 11g R2, referring to the Oracle 11g topic ). Finally, let's make a summary to introduce some of the new features in Oracle 11g R2, which are not very large, but also quite good.

Version-based redefinition

Oracle 11g R2 adds a powerful new tool that can detect any version of the application database object. Not all database objects support version-Based Management, but are private synonyms, views and almost all PL/SQL objects, including stored procedures, functions, types, type subjects, packages, package subjects, and triggers, the real benefit of version management is that it simplifies the deployment of a modified version of the application code to the production database. If a series of errors occur during deployment, it is easy to roll back all affected objects to the previous version.

Eliminates DDL restrictions on flash back Data Archiving

In the previous article, I thoroughly studied the new feature "flash back Data archiving Flashback Data Archive, FBDA)" of Oracle 11g R1, also known as "Total Recall) it only captures the changed data and places the data in a special set of objects, which constitute FBDA. When a user queries the history records of a table through the Flash version Flashback Versions query, oracle will directly return the latest changed data from the UNDO tablespace of the database and the old data from FBDA.

Although this feature is good, there are many restrictions in earlier versions, including adding, modifying, renaming, deleting table columns, truncate tables, modifying table constraints, and modifying Partition Table partition specifications. in Oracle 11g R2, all these restrictions are unavailable, for more complex DDL operations, such as using the DBMS_REDEFINITION package to redefine the basic tables already stored in FBDA, Oracle 11g R2 provides a new DBMS_FLASHBACK_ARCHIVE package, the stored procedure DISASSOCIATE_FBA separates the basic table from FBDA. Once the request changes, the stored procedure REASSOCIATE_FBA is used to reassociate the modified table and the basic table.

Create segments as needed

In earlier versions, when you use the create table statement to CREATE a TABLE, the sequence segment of the TABLE is automatically created at the same time. This default behavior has changed since Oracle 11gR2, the sequence segment is not created when a table is created until data is inserted into the table. In addition, no indexes or LOB segments dependent on the table will be created until data is inserted. The default behavior is specified in the table's segment creation deferred storage attribute, however, you can use the segment creation immediate attribute to overwrite it.

The size of the unavailable index is zero.

When you reload a large table, such as a fact table in a data warehouse with millions of rows, you must increase the loading speed of the table, the simplest way is to make all the indexes on the table unavailable. After the data is loaded, Oracle 11g R2, and takes substantive measures, when the index is marked as unavailable, it will automatically delete all index segments.

Summary

Oracle 11g R2 continues the commendable features of self-management, self-adjustment, and self-healing since Oracle 10g. This new version provides many new features, some of which are delayed, some are innovative. Oracle DBAs can use these new features to improve work efficiency and become a real "information engineer ".

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Original article: The Second 5 top new features in Oracle Database 11g R2 Author: Jim Czuprynski