15.10 - DROP column_name - Teradata Database

Teradata Database SQL Data Definition Language Syntax and Examples

Teradata Database
Release Number
December 2015
Content Type
Programming Reference
Publication ID
English (United States)

The named column is to be removed from the table. 
You cannot drop the QITS column from a queue table. For a column-partitioned table, Teradata Database drops the specified column from its column partition. 
If the specified column is the only column in the column partition, and the partition is not the only column partition, Teradata Database drops the partition. You cannot drop a column partition with a single column when it is the only column partition defined for the table or join index.

You cannot drop a column in use as the begin column or end column of a derived period column.

For information about dropping temporal columns, see Temporal Table Support, B035-1182.

The identity column attribute for the named column is to be removed from the table. 
The specification of IDENTITY is optional.
You can drop an identity column from an existing table. 
When you use Unity Director, you cannot do a bulk data load insert of rows into a table that has an identity column. However, you can specify this option to drop only the identity column attribute while retaining the column and data. This is useful when the identity column for a table is also its unique primary index.

Unity Director provides its own mechanism for generating identity column-like values for tables that require the identity column functionality and which are accessed through Unity Director. For additional information, see the Unity documentation.