Partitioned Tables   «Prev  Next»
Lesson 1

Introduction to Oracle Partitioned Tables

Partitioned tables are an Oracle feature that can dramatically improve a variety of database operations, from 1) query execution to 2) backup and recovery to 3) higher availability. This module introduces:
  1. Reasons for partitioning
  2. Advantages of partitioned tables
  3. How to partition on a range of values
  4. How to index a partitioned table
  5. The differences between local and global indexes
  6. How to merge, split, and drop partitions

Introduction to Partitioning

Partitioning addresses key issues in supporting very large tables and indexes by letting you decompose them into smaller and more manageable pieces called partitions, which are entirely transparent to an application. SQL queries and DML statements do not need to be modified in order to access partitioned tables. However, after partitions are defined, DDL statements can access and manipulate individual partitions rather than entire tables or indexes. This is how partitioning can simplify the manageability of large database objects.
Each partition of a table or index must have the same logical attributes, such as column names, datatypes, and constraints, but each partition can have separate physical attributes such as compression enabled or disabled, physical storage settings, and tablespaces. Partitioning is useful for many different types of applications, particularly applications that manage large volumes of data. OLTP systems often benefit from improvements in manageability and availability, while data warehousing systems benefit from performance and manageability.