Optional structures that make data retrieval more efficient, including indexes, materialized views, dimensions, and clusters, are also described. This chapter describes how partitioning can be used to split large tables and indexes into more manageable pieces. This chapter gives an overview of the object extensions that Oracle provides. This chapter describes the extensions to views provided by the Oracle data server. This chapter defines the concept of transactions and explains the SQL statements used to control them.
Transactions are logical units of work that are executed together as a unit.
This chapter explains how Oracle manages the dependencies for objects such as procedures, packages, triggers, and views. This chapter introduces the optimizer, which is the part of Oracle that chooses the most efficient way to execute each SQL statement. This chapter explains how Oracle provides concurrent access to and maintains the accuracy of shared information in a multiuser environment. It describes the automatic mechanisms that Oracle uses to guarantee that the concurrent operations of multiple users do not interfere with each other. This chapter discusses data integrity and the declarative integrity constraints that you can use to enforce data integrity.