Use bit columns for true/false or yes/no types of data. bit columns hold either 0 or 1. Integer values other than 0 or 1 are interpreted as 1. Storage size is 1 byte. Multiple bit datatypes in a table are collected into bytes. For example, 7-bit columns fit into 1 byte; 9-bit columns take 2 bytes.
Columns of datatype bit cannot be NULL and cannot have indexes on them. The status column in the syscolumns system table indicates the unique offset position for bit columns.
