ORA-01488: invalid nibble Don Burleson

The ORA-01488, invalid nibble (An impossible request for decimal to binary conversion was made) message usually indicates a data conversion issue within an Oracle application, usually PL/SQL or SQL*Loader mapping to an Oracle table column. Each byte (character) in a zoned decimal field contains two 4-bit nibbles. Each nibble must have a valid value.

Within SQL*Loader (sqlldr) you may also see “Invalid packed decimal nibble” as an equivalent error message, or these nibble errors from various sources:

• ORA-02357: Packed Decimal conversion error

• ORA-07409: slpdtb: invalid packed decimal nibble

• SQL*Loader-641 invalid zoned decimal nibble

• M0012 dllname: Translate with forward/backward mapping name, conversion error between structure element name and interface element name: Invalid nibble: nibble (half byte) (hex).

The “invalid nibble” error is usually associated with an improper conversion such as mapping an integer to a decimal data type or improper mapping of a packed decimal mapping to a FLOAT datatype.

For mapping external data, the Oracle docs note:

The numeric EXTERNAL datatypes are the numeric datatypes (INTEGER, FLOAT, DECIMAL, and ZONED) specified with the EXTERNAL keyword, with optional length and delimiter specifications.

Sometimes the “invalid nibble” can be caused by an incorrect NLS_LANG setting for the database, where an Oracle tables column was expecting a "," and not a decimal.