Default Database | SQL Fundamentals | Teradata Vantage - The Default Database - Advanced SQL Engine - Teradata Database

The default database is a Teradata extension to SQL that defines a database that is used to look for unqualified names, such as table, view, trigger, or macro names, in SQL statements.

If the unqualified object name exists in more than one of the databases in which Teradata Database looks, the SQL statement produces an ambiguous name error.

Establishing a Permanent Default Database

You can establish a permanent default database that is invoked each time you log on.

For example, the following statement automatically establishes Personnel as the default database for Marks at the next logon:

MODIFY USER marks AS
DEFAULT DATABASE = personnel ;

After you assign a default database, Teradata Database uses that database as one of the databases to look for all unqualified object references.

To obtain information from a table, view, trigger, or macro in another database, fully qualify the table reference by specifying the database name, a FULLSTOP character, and the table name.

Establishing a Default Database for a Session

You can establish a default database for the current session that Teradata Database uses to look for unqualified object names in SQL statements.

For example, after entering the following SQL statement:

DATABASE personnel ;

you can enter a SELECT statement:

SELECT deptno (TITLE 'Org'), name
FROM employee ;

which has the same results as:

SELECT deptno (TITLE 'Org'), name
FROM personnel.employee;

To establish a default database, you must have some privilege on an object in that database. Once defined, the default database remains in effect until the end of a session or until it is replaced by a subsequent DATABASE statement.

Default Database for a Stored Procedure

Stored procedures can contain SQL statements with unqualified object references. The default database that Teradata Database uses for the unqualified object references depends on whether the CREATE PROCEDURE statement includes the SQL SECURITY clause and, if it does, which option the SQL SECURITY clause specifies.

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