The BIT data type holds a variable length string of binary digits.
It is commonly used to represent arbitrary binary data that does not contain
an exact number of bytes. A bit string literal consists of the letter B, followed
by a string of binary digits enclosed in single quotation marks, as in the
following example:
B'0100101001'
Any number of
digits, which must be either 0 or 1, can be specified. The initial B can be
specified in uppercase or lowercase.