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Informix Error -431

-431 Type float does not match size.

This internal error indicates a problem in the communication between the database server and the library functions that call it. Check that your program is at the same software level as the database server in use. If the error recurs, note all circumstances and contact IBM Informix Technical Support.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-431 is the floating-point counterpart of -430: another internal client/server communications error signaling a breakdown between the database server and calling library functions, most commonly from a software-version mismatch.

  1. A client library compiled/linked against a different server version than the one actually being connected to.
  2. A driver or client library bug in how floating-point type sizes are encoded/decoded across the wire protocol.
  3. Cross-platform floating-point representation assumptions gone wrong between client and server environments.
Solutions / Resolution
  1. Ensure the client program and database server operate at identical software versions, per the official guidance — the primary, most actionable check.
  2. If the problem persists after confirming version alignment, document all relevant details and reach out to IBM Informix Technical Support, per the official guidance.
  3. Check for a client driver/library update if the error recurs consistently with a specific client.
Examples
Confirming client/server software-level alignment
-- Compare the client library's compiled/linked version against
-- the actual connected server version before assuming a deeper
-- bug is involved.
Documenting circumstances for escalation
- Client driver and version in use
- Server version
- Exact statement being executed
- Frequency: one-off or reproducible?
Diagnostic Checks
  1. Confirm client/server software-level compatibility.
  2. Check for available client driver/library updates.
  3. Confirm whether the error is a one-off or reproducible.
Related Errors / Related Topics
  • -430 — "Type integer does not match size." The closest sibling — the identical underlying class of internal communications error, for integer types instead of floating-point.
  • -403 — "The size of a received row disagrees with the expected size." Another internal communications-level error in the same general protocol family.

Same resolution as -430 — check client/server software-level alignment first, then escalate to IBM Informix Technical Support if the mismatch persists.