16.20 - SHOWCOMPRESS Enhancements - Teradata Database - Teradata Vantage NewSQL Engine

Teradata Vantageā„¢ NewSQL Engine Release Summary

Teradata Database
Teradata Vantage NewSQL Engine
Release Number
March 2019
Content Type
Release Notes
Publication ID
English (United States)
Last Update
The Ferret SHOWCOMPRESS command has two new output display options that provide additional information about table data compression:
  • /S displays the table ID's, table name and subtable ID's of the compressed and uncompressed tables.
  • /L displays the compression state, compression algorithm, compression level, exact compression ratio, exact % of blocks, exact used GB, and exact % of data, in addition to the information provided by the /S option.


  • The new /L display option allows you to determine exactly how much data in a table is compressed and uncompressed, and the exact compression ratio. (The related SHOWBLOCKS command provides only estimates based on a small sample of the table data.)
  • Because the /L option displays the algorithm used to compress the data, you can:
    • Validate that the correct algorithm has been used based on the data types of the table columns
    • Compare the space-saving benefits of different compression algorithms


  • SHOWCOMPRESS /L can require a long time for large systems, because it must traverse each data block to obtain exact compression statistics.

Additional Information

For more information on block-level compression, see Teradata Vantageā„¢ - Database Design, B035-1094.