Character data types are strings of characters. Upper and lower case alphabetic characters are accepted literally. There is one fixed-length character data type: char, and two variable-length character data types: varchar and long varchar.

The maximum length of a character column cannot exceed 32,000 bytes for a non-UTF-8 installation and 16,000 bytes for a UTF-8 installation.

Fixed-length char strings can contain any printing or non-printing character, and the null character ('\0'). Char strings are padded with blanks to the declared length.

Leading and embedded blanks are significant when comparing char strings. For example, the following char strings are considered different:

Length is not significant when comparing char strings; the shorter string is (logically) padded to the length of the longer. For example, the following char strings are considered equal:

Varchar strings are variable-length strings. The varchar data type can contain any character, including non-printing characters and the ASCII null character ('\0').

Except when comparing with char data, blanks are significant in the varchar data type. For example, the following two varchar strings are not considered equal:

and

If the strings being compared are unequal in length, the shorter string is padded with trailing blanks until it equals the length of the longer string.

For example, consider the following two strings:

where:

'\001' represents one ASCII character (ControlA)

and

If they are compared as varchar data types, then

because the blank character added to 'abcd' to make the strings the same length has a higher value than ControlA ('\040' is greater than '\001').

The intrinsic Ingres DBMS long varchar data type is supported in OpenROAD through the LongVarcharObject system class. For more information, see LongVcharObject Class.