Multivalue Compression Procedure - Teradata Vantage

1. Use the COMPRESS phrase in a CREATE TABLE or ALTER TABLE statement to specify a list of frequently occurring values for the column that contains the values, for example:

   CREATE TABLE Employee
      (EmpNo INT NOT NULL,
       EmpLoc CHAR(30) COMPRESS ('Seattle','Dallas','Chicago')
   ...
       DOB DATE COMPRESS (DATE '1972-02-29', DATE '1976-02-29')
   ...);

2. The system compresses the specified values when data moves into the table, and uncompresses the values when the containing rows are accessed.

You can use MVC to compress columns with these data types:

• Any numeric data type
• BYTE
• VARBYTE
• CHARACTER
• VARCHAR
• DATE

  To compress a DATE value, you must specify the value as a Date literal using the ANSI DATE format (DATE 'YYYY-MM-DD'). For example:

      COMPRESS (DATE '2000-06-15')
     

• TIME and TIME WITH TIME ZONE
• TIMESTAMP and TIMESTAMP WITH TIME ZONE

To compress a TIME or TIMESTAMP value, you must specify the value as a TIME or TIMESTAMP literal. For example:

   COMPRESS (TIME '15:30:00')

   COMPRESS (TIMESTAMP '2006-11-23 15:30:23')