You can compress a set of join index column values that repeat often across rows. This is referred to as row compression. Group the columns with repeating values. Then, group the columns with values that do not repeat frequently. This non-repeating column set is called the fixed column set.
You can configure row compression for a join index. In the join index definition, group the set of repeating columns in parenthesis, then group the fixed set of columns in parenthesis, separating the two groups with a COMMA character.
The join index t3_jindx in Example: Creating Join Indexes With a UDT Column as a Primary or Secondary Index is a simple example of how to create a row-compressed join index.
For a detailed explanation of join index row compression, see “Row Compression of Join Indexes” in Teradata Vantage™ SQL Data Definition Language Detailed Topics , B035-1184 .
You cannot specify row compression for a partitioned join index.