The VARCHAR2 data type stores variable-length character literals. A literal is a fixed data value.

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For example, 'LILA', 'St. George Island', and '101' are all character literals; 5001 is a numeric literal. Character literals are enclosed in single quotation marks so that the database can distinguish them from schema object names.

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Note

This manual uses the terms text literal, character literal, and string interchangeably.

When you create a table with a VARCHAR2 column, you specify a maximum string length. In Example 2-1, the last_name column has a data type of VARCHAR2(25), which means that any name stored in the column has a maximum of 25 bytes.

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For each row, Oracle Database stores each value in the column as a variable-length field unless a value exceeds the maximum length, in which case the database returns an error. For example, in a single-byte character set, if you enter 10 characters for the last_name column value in a row, then the column in the row piece stores only 10 characters (10 bytes), not 25. Using VARCHAR2 reduces space consumption.

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In contrast to VARCHAR2, CHAR stores fixed-length character strings. When you create a table with a CHAR column, the column requires a string length. The default is 1 byte. The database uses blanks to pad the value to the specified length.

Oracle Database compares VARCHAR2 values using nonpadded comparison semantics and compares CHAR values using blank-padded comparison semantics.