CUBE Grouping Set Option - Teradata Database

Purpose

Analyzes data by grouping it into multiple dimensions.

Syntax

Syntax Elements

ordinary_grouping_set

one or more expressions used to group cubed report rows across multiple dimensions.

All ordinary grouping sets must make explicit column references. You cannot specify column positions with CUBE.

You cannot specify more than 8 columns in the ordinary grouping sets.

This limit is actually on the number of table dimensions that can be cubed. The value is much smaller than the limits for the ROLLUP and GROUPING SETS options because it specifies a limit of 28, or 256 different combinations of columns, not just columns.

You cannot reference columns that have a LOB data type unless they are first CAST to another type or passed to a function whose result is not a LOB. For example, casting a BLOB to BYTE or VARBYTE or a CLOB to CHARACTER or VARCHAR.

ANSI Compliance

CUBE is ANSI SQL:2011 compliant.

Rules and Restrictions for CUBE

You cannot specify a SAMPLE clause in a query that specifies the CUBE option in a GROUP BY clause, with the exception of a query where the CUBE option in the GROUP BY clause appears in a derived table or view and the SAMPLE clause appears in the outer query.

How CUBE Summarizes Data

Given n dimensions, CUBE generates 2n different kinds of groups. Teradata Database reports each group as a single row.

For example, with 2 dimensions, CUBE generates 4 groups as follows:

With 3 dimensions, CUBE generates 8 groups as follows:

Example: CUBE Grouping

Suppose you have the following sales_view table data:

You are interested in determining the effect of county and PID on sale price.

The following SELECT statement analyzes the effect of county and PID on sale price using CUBE in its GROUP BY clause:

     SELECT pid, county, SUM(sale)
     FROM sales_view
     GROUP BY CUBE (pid,county);

The query reports the following data, where the QUESTION MARK character indicates a null:

PID

County

Sum(sale)

---

------

---------

2

Los Angeles

24750

1

Los Angeles

164475

2

San Diego

5940

1

San Diego

154155

2

?

30690

1

?

381630

?

Los Angeles

189225

?

San Diego

160095

?

?

349320

Notice that nulls are used to represent the empty set, not missing information. The nulls mean that information is not reported at the grouping level represented, not that the information is missing from the sales_view base table.