Oninit
Talk to an expert →

Informix Error -9406: Cannot resolve support function for user-defined aggregate <aggregate-name>.

Cause and resolution

Cannot resolve support function for user-defined aggregate <aggregate-name>.

You attempted to use a built-in aggregate for which the database server could not find an appropriate support function. For example, if you try to use the SUM aggregate on the "new_type" data type, the database server looks for the following operator function:

plus(new_type, new_type)

This error can also occur for a user-defined aggregate when one of the support functions that the CREATE AGGREGATE statement has listed (INIT/ITER/COMBINE/FINAL) is missing.

Make sure that you have the correct support functions for the user-defined aggregate. These functions must be exist and must be registered in the database with CREATE FUNCTION.

</aggregate-name>

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-9406 fires when the database server can't find an appropriate support function for a built-in or user-defined aggregate — per the official guidance.

  1. A built-in aggregate applied to a UDT with no matching operator function — e.g. SUM on new_type requiring a plus(new_type, new_type) function — per the official guidance.
  2. A user-defined aggregate missing one of its listed support functions (INIT/ITER/COMBINE/FINAL), per the official guidance.
Solutions / Resolution
  1. Make sure the correct support functions exist and are registered with CREATE FUNCTION, per the official guidance.
Examples
Using SUM on a UDT with no plus() function
SELECT SUM(geom_col) FROM tab;
-- -9406 if no plus(new_type, new_type) function is registered
Corrected — registering the missing support function
CREATE FUNCTION plus(c1 new_type, c2 new_type) RETURNING new_type
   ...;
Diagnostic Checks
  1. Check the system catalog for the expected support function's exact name/signature, and register it with CREATE FUNCTION if missing.
Related Errors / Related Topics
  • -9401 — "Cannot re-define or drop builtin aggregate ." A related aggregate-support error, on forbidden redefinition rather than a missing support function.
  • -9412 — "Return type of the support function does not match the aggregate state type." A related aggregate-support-function error, on return-type mismatch rather than the function being entirely missing.

A required support function for the aggregate couldn't be found — register it with CREATE FUNCTION, matching the expected signature.