Overview of Managing Objects |
You need to create tables, indexes, and possibly other database objects in a schema before you start developing your application. A schema is a collection of database objects. A schema is owned by a database user and has the same name as that user, such as the HR schema. Schema objects are logical structures created by users. Objects can define areas of the database to hold data, such as tables or indexes, or can consist just of a definition, such as a views or synonyms.
Database Objects: Usage Information discusses tables, indexes, views, sequences, and synonyms. Other database (schema) objects include functions, packages, procedures, and triggers. Functions, packages, and procedures are discussed in Subprograms and Packages: Usage Information. Triggers are discussed in Triggers: Usage Information.
Some object types have many more management options than others, but most have a number of similarities. Every object in the database belongs to just one schema and has a unique name within that schema. Therefore, when you create an object, you must ensure it is in the schema where you intend to store it. Generally, you place all of the objects that belong to a single application in the same schema.
A database object name must abide by certain rules, including the rule that it must be unique within its schema. For example, object names cannot be longer than 30 bytes and must begin with a letter. If you attempt to create an object with a name that violates any of these rules, then Oracle raises an error.
To include lowercase characters, special characters, or spaces in an object name, you must enclose the name in quotation marks (" ") when you type it in a Name field in SQL Developer. Example: "My table"
The following topics describe how to view, create, and manage the various types of objects in your database schemas: