ORA-12899: value too large for column

ORA-12899: value too large for column "SCHEMA"."TABLE"."COLUMN" (actual: N, maximum: M)

A value is longer than the column allows. The message shows the actual and maximum length. With multi-byte data, a column sized in BYTE can overflow even when the text looks short enough — Turkish letters such as ğ, ş and ı take two bytes in AL32UTF8.

What it means

Every VARCHAR2 and CHAR column has a maximum length, in bytes or in characters. When an INSERT or UPDATE would exceed it, Oracle rejects the statement and reports both lengths, e.g. (actual: 23, maximum: 20). If the length is in BYTE and the database character set is AL32UTF8, every non-ASCII character counts as two or more bytes.

Common causes

• The incoming value is simply longer than the column.
• Byte length semantics with multi-byte characters: VARCHAR2(20) holds 20 bytes, which may be fewer than 20 characters.
• Data migrated from a single-byte character set to AL32UTF8.
• An application that does not validate input length.

How to fix it

1. Compare the actual and maximum values in the message to see how much is missing.
2. Enlarge the column, preferably with character semantics: ALTER TABLE t MODIFY (col VARCHAR2(50 CHAR)).
3. Check lengths in bytes and characters: LENGTHB(col) vs LENGTH(col).
4. Validate or truncate input in the application if the limit is intentional.

Example

Bytes vs characters (AL32UTF8):

SELECT LENGTH('Gümüşhane') AS chars, LENGTHB('Gümüşhane') AS bytes FROM dual;
-- chars = 9, bytes = 12

Size the column in characters:

ALTER TABLE customers MODIFY (city VARCHAR2(50 CHAR));

In SQLlightspeed

When a statement fails, SQLlightspeed’s error panel shows the error code with a plain-language explanation and a suggestion for what to do next, together with Oracle’s own message and a link to Oracle’s documentation — for this error and dozens of other common ones.

Related errors

ORA-06502ORA-01400ORA-01722 All Oracle errors →

Oracle documentation for ORA-12899. Oracle is a registered trademark of Oracle Corporation. SQLlightspeed is not affiliated with Oracle.