File status 22: Duplicate key

What it means

Status 22 is an invalid key condition, and the record was not written. It applies to indexed files (VSAM KSDS) and relative files (VSAM RRDS). QSAM and line-sequential files have no keys and can't return it.

There are three ways to hit it. A WRITE uses a prime key that's already in the file. A WRITE or REWRITE gives an alternate key a value that already exists, and that alternate key wasn't declared WITH DUPLICATES. Or, on a relative file, a WRITE targets a relative record number whose slot already holds a record.

VSAM reports the condition as register 15 = 8 with feedback code 8 (X'08'), an attempt to store a record with a duplicate key. If data-name-8 is coded on the FILE STATUS clause, it holds those values. The INVALID KEY phrase runs if it's coded. If the duplicate is in an alternate key declared WITH DUPLICATES, there's no error at all, and the program sees 02 instead.

Common causes

• A rerun after a failure. The first run added some records before it stopped, and the rerun tries to add them again.
• The input holds the same key twice, for example a transaction file with repeated entries.
• The program means to update an existing record but uses WRITE instead of REWRITE.
• An alternate index was defined UNIQUEKEY, but the data now has two records with the same alternate value.
• The key field wasn't filled correctly, so many records get the same key, often spaces or zeros.

How to find the problem

1. DISPLAY the key of the failing record. Then READ the file with that key, or look it up with a file browse tool, to see the record that's already there.
2. If the prime key isn't a duplicate, check the alternate keys. IDCAMS LISTCAT ALL on each alternate index shows whether it's UNIQUEKEY and whether it's in the upgrade set.
3. Display data-name-8. Return code 8 with feedback code 8 confirms a duplicate key at the VSAM level.
4. For a rerun, check the restart logic and how far the failed run got before it stopped.

How to fix it

• For add-or-update logic, READ first and choose WRITE or REWRITE from the result. Or try the WRITE and, on 22, READ the record and REWRITE it.
• Make the job safe to rerun. Restore the file from a backup taken before the failed run, or skip keys that already exist.
• Remove duplicate input before the update with a sort step, for example DFSORT with SUM FIELDS=NONE.
• If duplicate alternate keys are valid, redefine the alternate index NONUNIQUEKEY and add WITH DUPLICATES to the ALTERNATE RECORD KEY clause.

Last reviewed 2026-10-18 by the WND Software team. Written in our own words. For the full reference, check IBM’s Enterprise COBOL documentation for your release.