Multivalue compression (MVC) compresses repeating values in a column when you specify the value in a compression list in the column definition.
When data in the column matches a value specified in the compression list, the database stores the value only once in the table header, regardless of how many times it occurs as a field value for the column. The database then stores a smaller substitute value, often as small as 2 bits, in each row where the value occurs.
MVC generally provides the best cost/benefit ratio compared to other methods. Because it requires minimal resources to uncompress the data during query processing, you can use MVC for hot (frequently used) data without compromising query/load performance. MVC is also considered the easiest to implement of all the compression methods.
MVC is a logical data compression form and is lossless.
Besides storage capacity and disk I/O size improvements, MVC has the following performance impacts: