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Lesson 4 Features for large databases
Objective Describe features for large databases.

Large Databases using Oracle Administration

A variety of features and enhancements in Oracle9i improve efficiency for larger databases, for example, better handling of data loading and table storage. The table below lists these items and their benefits. Later on in this course, you will get a chance to practice most of these new elements. Observe the slide show below to see the four major enhancements that help you work with large databases.

  1. SQL * Loader now handles object tables, collections, and LOBs large objects
  2. New MOVE clause in the ALTER TABLE command makes it possible to reorganize a table without losing all its relationship and grants.
  3. New parameter in the CREATE TABLE command allows you to create a temporary table whose data is only seen by your session
  4. New DROP COLUMN clause on the ALTER TABLE command allows you to remove unused columns without dropping and recreating your table

Large Database Enhancements

What is a Large Database?

Let us begin by describing what we mean by a large database. Large is a relative term that changes over time. What was large five or ten years ago is small by today's standards, and what is large today will be considered small a few years from now. Each release of Oracle has included new features and enhancements to address the need to store more and more data. For example, Oracle was released in 1999 and could handle databases with terabytes (1024 gigabytes) of data. In 2001, Oracle9i was released and could deal with up to 500 petabytes (1024 terabytes). Oracle Database 10g now offers support for exabyte (1024 petabytes) databases. You will not come across too many databases with exabytes of data right now, but in the future at least we know Oracle will support them. The most obvious examples of large database implementations are data warehouses and (DCS) decision support systems.
These environments usually have tables with millions or billions of rows, or wide tables with large numbers of columns and many rows. There are also many OLTP systems that are very large and can benefit from the features we are about to cover.