Lesson 1

The Oracle enhancements have made the basic tasks of managing the size and location of database storage space more challenging. For example, you have always had to determine what size to make a tablespace, but now you must also determine how the space within the tablespace is to be managed (centrally or locally), whether the tablespace can be moved from one database to another, and more.

• Module Objectives
  By the end of the module you will be able to:
  1. Describe the purpose of tablespace management
  2. Create locally managed tablespaces
  3. Create transportable tablespaces
  4. Describe new features for READ ONLY tablespaces
  5. Identify the enhancements to the Database Resource Manager
  6. Use the Database Resource Manager to limit resource usage
  
  This module describes how to use the newest tablespace and resource management features of Oracle.
  Many of these features are aimed at better use of storage space and faster retrieval of data.

In Oracle, tablespace management is essential for organizing and managing the storage of data within the database. Tablespaces are logical storage units that group related data files, making it easier to allocate, monitor, and manage disk space. Here are key purposes of tablespace management:

1. Efficient Storage Allocation: Tablespaces allow DBAs to allocate storage to various objects, such as tables, indexes, and other data structures, ensuring that each part of the database has adequate space without over-allocating.
2. Data Segmentation: By using different tablespaces, you can separate and organize data by function or type, such as storing application data, temporary data, and system data in separate areas, which improves performance and manageability.
3. Performance Optimization: Proper tablespace management enables efficient use of disk I/O. By strategically placing high-usage tables and indexes in separate tablespaces, you can reduce contention and improve query performance.
4. Backup and Recovery: Tablespaces can be managed independently, so you can perform backups and restore specific tablespaces rather than the entire database, reducing downtime and increasing flexibility.
5. Space Monitoring and Maintenance: Tablespaces allow DBAs to monitor space usage, allocate additional space, or reclaim unused space. This ensures that the database operates smoothly without unexpected storage issues.

In Oracle 11g, tablespace management can be locally managed (the default), which uses bitmaps to track free space, or dictionary-managed (an older method), which relies on data dictionary tables. Local management is preferred due to improved performance and reduced contention.

Each database requires at least one (DBA) database administrator and an Oracle Database system 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:

1. Installing and upgrading the Oracle Database server and application tools
2. Allocating system storage and planning future storage requirements for the database system
3. Creating primary database storage structures (tablespaces) after application developers have designed an application
4. Creating primary objects (tables, views, indexes) once application developers have designed an application
5. Modifying the database structure, as necessary, from information given by application developers
6. Enrolling users and maintaining system security
7. Ensuring compliance with Oracle license agreements
8. Controlling and monitoring user access to the database
9. Monitoring and optimizing the performance of the database
10. Planning for backup and recovery of database information
11. Maintaining archived data on tape
12. Backing up and restoring the database
13. Contacting Oracle for technical support

The next lesson answers the question, What is the purpose of tablespace management?