SQLCODE -818 consistency token mismatch

SQLCODE -818: consistency token mismatch — the load module and the package were built from different source versions.

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

• Program recompiled but not rebound, or bound from a different compile.
• Stale load module in the load library.

How to diagnose

• Compare timestamps: load module link date vs package bind timestamp.
• Check which library the program actually loaded from.

How to fix it

• Recompile, then BIND/REBIND so tokens match.
• Deploy the matching load module and package together.

Example: Keep compile and bind in lockstep

Token mismatches always mean the pair is out of sync.

Interview tip

• Q: How would you troubleshoot a SQLCODE -818 consistency token mismatch 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.