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Lesson 1

Oracle improvements for DBA

Throughout this series we have seen a number of improvements provided by Oracle. This module discusses the benefits to Database Administrators (DBAs). From loading data to dropping columns from tables, Oracle not only saves the DBA a lot of time and effort, but also includes new features that make the database more flexible.

Module objectives

By the end of this module you will be able to:
  1. List improvements to SQL*Loader
  2. Load large object (LOB) data with SQL*Loader
  3. Describe enhancements in table management
  4. Relocate a table
  5. Describe why and how to create a temporary table
  6. Find and remove an unused column from a table
  7. List new database limits
In the next lesson we will look at the improved SQL*Loader utility.

SQL*Loader Features

SQL*Loader loads data from external files into tables of an Oracle database. It has a powerful data parsing engine that puts little limitation on the format of the data in the datafile. You can use SQL*Loader to do the following:
  1. Load data across a network. This means that you can run the SQL*Loader client on a different system from the one that is running the SQL*Loader server.
  2. Load data from multiple datafiles during the same load session.
  3. Load data into multiple tables during the same load session.
  4. Specify the character set of the data.
  5. Selectively load data (you can load records based on the records' values).
  6. Manipulate the data before loading it, using SQL functions.
  7. Generate unique sequential key values in specified columns.
  8. Use the operating system's file system to access the datafiles.
  9. Load data from disk, tape, or named pipe.
  10. Generate sophisticated error reports, which greatly aid troubleshooting.
  11. Load arbitrarily complex object-relational data.
  12. Use secondary datafiles for loading LOBs and collections.
  13. Use either conventional or direct path loading. While conventional path loading is very flexible, direct path loading provides superior loading performance
A typical SQL*Loader session takes as input a control file, which controls the behavior of SQL*Loader, and one or more datafiles. The output of SQL*Loader is an Oracle database (where the data is loaded), a log file, a bad file, and potentially, a discard file. An example of the flow of a SQL*Loader session is shown in Figure 5-1.

Figure 5-1 SQL*Loader consisting of 1)Input Datafiles,2)Log File, 3) Database, 4) Loader Control File, 5) Bad Files, 6) Discard Files

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