This module deals with the new data type structures and explains their performance implications for Oracle databases.
Prior to the introduction of Oracle, critics were comparing the added functionality of the new object-oriented databases with the traditional relational database model.
With Oracle we see several new object-oriented data structures that promise faster performance.
In this module, we will take a closer look at these new features.
The next lesson reviews the new Oracle data structures.
By the time you finish this module, you will be able to:
List the functionality of each of the Oracle data structures
Create an Abstract Data Type (ADT)
Create a nested table
Define a table with a VARRAY
A database management system (DBMS) is software that controls the storage, organization, and retrieval of data. Typically, a DBMS has the following elements:
- Kernel code: This code manages memory and storage for the DBMS.
- Repository of metadata: This repository is usually called a data dictionary.
- Query language: This language enables applications to access the data.
A database application is a software program that interacts with a database to access and manipulate data.
The first generation of database management systems included the following types:
- Hierarchical: A hierarchical database organizes data in a tree structure. Each parent record has one or more child records, similar to the structure of a file system.
- Network: A network database is similar to a hierarchical database, except records have a many-to-many rather than a one-to-many relationship.
The preceding database management systems stored data in rigid, predetermined relationships. Because no data definition language existed,
changing the structure of the data was difficult. Also, these systems lacked a simple query language, which hindered application development.