Primary Index vs Secondary Index in Teradata

When discussing Teradata, it is important to understand the difference between primary index and secondary index.

Primary Index:

The primary index in Teradata is used to distribute the rows of a table across the AMPs (Access Module Processors) in a way that can optimize query performance. It is defined when creating a table and determines how data is physically stored in the system.

Secondary Index:

In contrast, a secondary index in Teradata is an additional index that can be defined on a table after it has been created with a primary index. Secondary indexes are useful for enhancing the performance of queries that do not reference the primary index columns.

Overall, while the primary index is crucial for data distribution and query optimization, secondary indexes provide additional flexibility for querying the data based on different criteria.

Understanding the distinction between primary index and secondary index is essential for effective data retrieval and query performance in Teradata.