Informix Error -874: General exception error has occurred in the optimizer.

Reasons / Common Causes

-874 is flagged by the official text as an internal error in the query optimizer, with no documented application-level trigger.

1. A genuine internal engine condition in the optimizer, per the official guidance's framing, with no other documented application-level cause.
2. An unusually complex or edge-case query exercising an uncommon optimizer code path, plausible given the general nature of optimizer-level errors elsewhere in this reference (like -640), though not explicitly named by this error's own sparse official text.

Solutions / Resolution

1. If this recurs, note all circumstances and contact IBM Support, per the official guidance — there is no documented general application-level fix.
2. Try UPDATE STATISTICS on the tables involved, as a practical first step given -640's precedent of a similar optimizer-related error being resolvable that way, even though not explicitly named for -874 itself.
3. Try simplifying the query, as a practical step to isolate which specific construct triggers the failure, if an unusually complex query was involved.

Examples

Trying UPDATE STATISTICS first

UPDATE STATISTICS FOR TABLE orders;
-- retry the statement that produced -874

Diagnostic Checks

1. Try UPDATE STATISTICS on the tables involved, given the precedent from -640.
2. Try simplifying the query if it's unusually complex.
3. Capture the exact statement for escalation if neither resolves it.

Related Errors / Related Topics

• -640 — "QPlan sanity failure line-number." A related optimizer-level internal error, where UPDATE STATISTICS is the official guidance's own documented first fix — a reasonable first step to try here too, though not explicitly named for -874.

An internal optimizer error — try UPDATE STATISTICS first (per -640's precedent), then simplify the query before escalating to IBM Support.