varchar

A varchar or Variable Character Field is a set of character data of indeterminate length. The term varchar specifically refers to a data type of a field (or column) in a database management system. Varchar fields can be of any size up to the limit. The limit differs from types of databases, an Oracle 9i Database has a limit of 4000 bytes, a MySQL Database has a limit of 65,535 bytes (for the entire row) and Microsoft SQL Server 2005 8000 bytes (unless varchar(max) is used, which has a maximum storage capacity of 2,147,483,648 bytes).

varchar data types are popular amongst all database management systems (DBMS). This is mostly because, unlike the fixed-size char data-type, varchar does not store any blank characters, reducing the size of a database when the full length of the field is not used, although the length of the used size is stored, adding a small overhead.

References

• CHAR and VARCHAR documentation for Microsoft SQL Server 2008.
• VARCHAR documentation for Apache Derby.
• CHAR and VARCHAR documentation for MySQL 5.1.
• CHAR and VARCHAR documentation for IBM_Informix.