New features for tablespace and resource management
Understand Oracle tablespace and resource management.
Tablespace and Resource Management in Oracle
New types of tablespaces
The tablespace features give you greater flexibility in controlling the physical location and availability of specific portions of the database.
Tablespace improvements allow faster and easier backups, better capabilities to change the status of tablespaces, and more choices for tablespace management.
Each database requires at least one database administrator (DBA). An Oracle Database system can be large and can have many users. Therefore, database administration is sometimes not a one-person job, but a job for a group of DBAs who share responsibility.A database administrator's responsibilities can include the following tasks:
Installing and upgrading the Oracle Database server and application tools
Allocating system storage and planning future storage requirements for the database system
Creating primary database storage structures (tablespaces) after application developers have designed an application
Creating primary objects (tables, views, indexes) once application developers have designed an application
Modifying the database structure, as necessary, from information given by application developers
Enrolling users and maintaining system security
Ensuring compliance with Oracle license agreements
Controlling and monitoring user access to the database
Monitoring and optimizing the performance of the database
Planning for backup and recovery of database information
Maintaining archived data on tape
Backing up and restoring the database
Contacting Oracle for technical support
Look at the slide show below to see an illustration of the new tablespace enhancements now available with Oracle.
To begin exploring new tablespace types, let us start with an example involving two databases, A and B.
This image shows the same two database after the two transportable tablespaces have been transported. Tablespace T-1 was transported from Database A to Database B.
Here is the second example. Database A contains two tablespaces, T-1 and T-2. User A has an active transaction using tablespace T-1.
With Oracle 8i, you can perform this change to READ ONLY status as soon as there are no outstanding transactions in the target tablespace.
In this third and final example, Database A contains the same two tablespaces, T-1 and T-2.
Oracle has enhanced tablespace management to allow for locally managed tablespaces. A locally managed tablespace does not use the data dictionary to track its open and used space
In addition to these features for tablespace management, the tool called the Database Resource Manager has been enhanced to allow the database administrator to control operating system resources. For example, the DBA can limit a user so the user is not allowed to use more than 40 percent of the CPU at any time. This prevents one user from "hogging" the CPU and causing other users to
experience long waits for services from the database. We will look into these features and improvements in a later module of this course.
About the Elements of Resource Manager
The elements of the Resource Manager include resource consumer groups, resource plans, and resource plan directives.
You use the DBMS_RESOURCE_MANAGER PL/SQL package to create and maintain these elements. The elements are stored in tables in the data dictionary. You can view information about them with data dictionary views. The next lesson describes storage-handling and space-handling efficiencies that have been added in Oracle.