Software-based BLC is designed for use on large volumes of seldom-accessed data. This is because access requires CPU-intensive decompression. BLC can also achieve relatively good compression on unknown/unclassified data across different column types, including the internal data structures and the row header. Teradata recommends that you do not load or access tables that use software-based BLC during peak hours (except on CPU-rich platforms).
Block-level compression can be enabled at the table level using SQL DDL. To enable block-level compression at the system level, contact Teradata Support.
- Temperature-Based Block-Level Compression
- Enabling Compression for Individual Tables Using DDL
- Setting the Compression Algorithm for Individual Tables Using DDL
- Setting the Software Compression Level for Individual Tables Using DDL
- Restrictions and Usage Notes
- Compressing Data Loaded into Empty Tables Set to MANUAL