17.00 - FROM source - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Definition Language Syntax and Examples

Advanced SQL Engine
Teradata Database
Release Number
September 2020
English (United States)
Last Update

For more information about the FROM clause, see Teradata Vantage™ - SQL Data Manipulation Language, B035-1146.

An optional database name if table_name is contained in a database other than the current database.
An optional user name if table_name is contained in a user other than the current or user.
The name of a table containing the column or columns to include in the join index or the name of a table to join with at least one other table to form a join index. You cannot define a join index on any of the following database objects:
  • Global temporary tables
  • Hash indexes
  • Join indexes
  • Journal tables
  • Ordinary views
  • Queue tables
  • Recursive views
  • Volatile tables
Each table in the FROM clause should have at least one column in either the fixed column_name list or in the repeating column_name list, if you are using row-compression.
In a single-table join index, the column_name list must contain all columns in the FROM clause table.
You can only define column partitioning for a single-table join index.
Each table name can be qualified by a database name if necessary and can have a maximum of 64 different columns referenced in the entire join index definition.
Every table must be connected to at least one other table with a join condition. The cross join and full outer join conditions are not supported.
The maximum number of table_name references allowed is the same as the system limit for SELECT requests.
A FROM clause can have any number of simple tables, but is limited to a single joined non-simple table expression. For example, you can use a simple table list or a single non-simple table expression:
FROM table_1, table_2, table_3,  table_4
FROM (table_1 INNER JOIN table_2 ON x1 = x2)
INNER JOIN (table_3 ON x1 = x3)
The following example is not allowed because it has more than one non-simple table expression:
 FROM (table_1 INNER JOIN table_2   ON table_1 x1 = x2),(table_3 
 INNER JOIN table_4 ON x3 = x4)
An alias for table_name.
The keyword AS preceding correlation_name is optional.