Altering Tables

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Use ALTER TABLE to modify the structure of an existing table. ALTER TABLE allows you to:

• Add a new column to a table.
• Drop a column from a table.
• Drop integrity constraints from a table or column.
• Modify the column name, data type, and position.

You can perform any number of the above operations with a single ALTER TABLE statement. A table can be altered by its creator, the SYSDBA user, and any users with operating system root privileges.

Note:
Any one table (and its triggers) can be altered at most 255 times before you must back up and restore the database.

Topics

• Before using ALTER TABLE
• Using ALTER TABLE

Advance To:

• Before using ALTER TABLE