Indexes

Best Practices for Indexes

The following best practices apply to indexes:

1)    Always use all upper case characters for column names.

2)     If you have a foreign key column, associate the foreign key table and the join column.

3)    DAC uses this information to identify all the related tables to be loaded when a certain table needs to be loaded in the data warehouse.

4)     For Teradata databases, pay attention to the Teradata Primary Index property.

■ For Teradata databases:

– Pay attention to the Teradata Primary Index property.

– Pay attention to which columns need to gather statistics. Note that column

statistics are some what equivalent to indexes.

– If you would have had indexes that span multiple columns for other

databases, consider defining multi-column statistics for Teradata.

■ Do not register any columns for source system container tables.

■ Make sure you add all the appropriate system columns. For example, all tables

should have the following:

– ROW_WID in number format.

– INTEGRATION_ID in varchar format.

– DATASOURCE_NUM_ID in number format.