A table is the basic logical structure in a database.
All data in your Oracle database is stored in a table and understanding how to manage tables is one of the basic skills for a database administrator.
This module will teach you to:
- Create a table
- Work with the basic Oracle datatypes
- Create a table using the Schema Manager
- Generate a list of the tables in your Oracle database
- Gather information about the columns in a table
- Modify a table by adding or modifying columns
- Delete a table
The table is the basic building block of your Oracle database, and so the information in this chapter is indispensable for working with your database.
A Schema Manager instance helps you with the abstraction of the generation of SQL assets such as Tables, Sequences, Foreign Keys and Indexes.
You should consider a schema to be the user account and collection of all objects therein as a schema for all intents and purposes.
For example,
SCOTT is a schema that includes the EMP, DEPT and BONUS tables with various grants.
SYS is a schema that includes tables, views, grants, and additional components.
SYSTEM is a schema.
Technically, a schema is the set of metadata (data dictionary) used by the database, typically generated using DDL. A schema defines attributes of the database, such as
- tables,
- columns, and
- properties.
A database schema is a description of the data in a database.