SQLCODE -904 unavailable resource

SQLCODE -904: unavailable resource — DB2 could not get something it needs (dataset, page set, log).

What it means

• After every EXEC SQL, DB2 returns a SQLCODE: 0 means success, +100 means no row found, and negative values mean an error.

Common causes

• Dataset for the table space is not available.
• Another system component holds the resource.
• Log dataset space issue.

How to diagnose

• Read SQLERRM: it names the unavailable resource.
• -DISPLAY DATABASE(*) SPACENAM(*) for object state.
• Check MVS for dataset enqueue or allocation problems.

How to fix it

• Make the dataset available (vary online, fix allocation).
• Resolve the competing holder.
• For log issues, involve the DBA immediately.

Example: Read SQLERRM first

SQLERRM is the fastest pointer to the real problem.

Interview tip

• Q: How would you troubleshoot a SQLCODE -904 unavailable resource in production?
• A: I would check the SQLCODE and SQLERRM immediately after the failing statement, reproduce in SPUFI, then apply the specific fix.

Prevention checklist

• Always check SQLCODE after every EXEC SQL statement.
• Log the SQLCODE, SQLSTATE and failing statement for support.