Informix Error -472

Reasons / Common Causes

-472 fires when a GET DESCRIPTOR/SET DESCRIPTOR (or similar) statement's VALUE (occurrence number) argument falls outside the valid range for the descriptor — it must be greater than zero and no larger than the number of occurrences the descriptor was actually allocated to hold (via ALLOCATE DESCRIPTOR ... WITH MAX).

1. A VALUE argument larger than the descriptor's allocated occurrence count — attempting to access an item slot beyond what was allocated.
2. A VALUE argument of zero or negative — occurrence numbers are 1-based, so these are never valid.
3. A loop iterating over descriptor items using the wrong upper bound, off by one or based on a stale/incorrect count.

Solutions / Resolution

1. Adjust the VALUE to be greater than zero and less than or equal to the available occurrences, per the official guidance, then retry the operation.
2. Check the descriptor's actual allocated occurrence count (via GET DESCRIPTOR ... COUNT) before looping over its items, rather than assuming a fixed or previously-cached count.
3. Review loop bounds iterating over descriptor items for off-by-one mistakes.

Examples

Checking COUNT before iterating

GET DESCRIPTOR 'desc1' :num_items = COUNT;
-- iterate from 1 to num_items, not an assumed fixed value

An out-of-range VALUE

GET DESCRIPTOR 'desc1' VALUE 15 :col_name = NAME;
-- -472 if desc1 was only allocated for (or actually holds) fewer
-- than 15 occurrences

Diagnostic Checks

1. Check the descriptor's actual occurrence count via GET DESCRIPTOR ... COUNT.
2. Compare the VALUE argument being used against that count.
3. Review loop bounds for off-by-one errors when iterating over descriptor items.

Related Errors / Related Topics

• -470 — "The value of occurrence must be greater than 0." A related occurrence-value restriction, at allocation time rather than at access time.
• -469 — "This descriptor does not exist." A related descriptor-usage error, about a missing allocation rather than an out-of-range access on an existing one.

Always check the descriptor's actual COUNT before accessing a specific occurrence — don't assume a fixed or previously-cached occurrence count still applies.