The select list of a join index specification defines the list of columns and expressions that make up the definition for the index.
You can also use the select list of your join index definition to create an aggregate join index by using the SUM, MIN, MAX, and COUNT aggregate functions.
The SELECT clause projects the columns from one or more base tables that are to be included in the join index definition.
- TOP n, FULL OUTER JOIN, CROSS JOIN, HAVING, QUALIFY, and SAMPLE
- Any function except RANDOM
- Statistical functions
- Aggregate functions other than SUM and COUNT
- Set operators UNION, EXCEPT/MINUS, INTERSECT, and their derivatives
- Subqueries
You cannot specify an EXPAND ON clause in the definition of a join index.
You cannot invoke an SQL UDF anywhere in the definition of a join index.
Certain optional clauses do not become part of the join index definition, for example, output FORMAT and TITLE phrases. You can determine if an option you specify does not become part of the stored join index definition by performing a SHOW JOIN INDEX request to view the DDL for the CREATE JOIN INDEX statement.
For a complete description of the SELECT statement, see Teradata Vantage™ - SQL Data Manipulation Language, B035-1146.
- COLUMN
- Column format for storing a column partition.
- ROW
- Row format for storing a column partition.
- AUTO COMPRESS
- NO AUTO COMPRESS
- If you do not specify AUTO COMPRESS or NO AUTO COMPRESS, Vantage uses the autocompression value specified after COLUMN keyword that begins the column partitioning specification. If you do not specify an autocompression value there, the system default is AUTO COMPRESS.