Compression in Teradata

Compression in Teradata plays a very important role in saving some space and increasing the performance of SQL Query. In Teradata, COMPRESSION can be implemented in three ways: a) Single Value or Multi Value Compression (MVC) b) Algorithmic Compression (ALC) c) Block – Level Compression (BLC) a) Single Value or Multi Value Compression: This type of compression is widely used in many Teradata Data Warehouse environment. This is easy to implement and can save good amount of space. MVC uses a dictionary to maintain value of data and its corresponding bit pattern. So while saving, Teradata replace the exact value with the bit pattern andRead More →

Compression in Teradata

Implementing COMPRESSION in Teradata is the best method for freeing some space in Teradata WareHouse environment. Compression Technique in Teradata has been there for sometime now and with every new release Teradata is working on it to make it more and more useful. Guidelines for implementing Compression in Teradata are as follows: a) Compression is valid only for FIXED width columns. b) The length limit for CHAR columns is 255 characters or less. c) The columns should not be a part of PRIMARY INDEX. d) Adding COMPRESS to any column will by default COMPRESS NULL’s. e) COMPRESS values are CASESPECIFIC , so COMPRESS ‘RAJ’ willRead More →