Informix Error -844

Reasons / Common Causes

-844 fires when the interactive tool can't allocate a large enough memory buffer to hold a statement — per the official guidance, the documented fix is to shorten the statement or split it into parts.

1. A very long, single statement (extensive generated SQL, a huge IN list, deeply nested expressions) exceeding what the interactive tool's buffer can hold — the direct, common cause, similar in nature to -762's parser stack overflow but at the buffer-allocation level.
2. Limited available memory on the client machine, making even a moderately long statement exceed what can currently be allocated.

Solutions / Resolution

1. Find a way to shorten the statement, per the official guidance — the same techniques suggested for -762 apply here too (replacing long OR chains with IN (...), for example).
2. Run it in two or more parts, per the official guidance, if the statement can be broken into separable pieces (staged through a temp table, for instance).

Examples

Splitting a long statement

-- Instead of one enormous statement combining many conditions:
SELECT * FROM orders WHERE order_id IN (1, 2, 3, /* ... thousands more ... */);

-- Stage the ID list into a temp table first, loaded separately, then join:
SELECT o.* FROM orders o, target_ids t WHERE o.order_id = t.order_id;

Diagnostic Checks

1. Check the statement's actual length and look for opportunities to shorten it (replacing long OR/IN lists, splitting into a staged multi-step process).

Related Errors / Related Topics

• -762 — "Stack overflow occurred during statement parse." A related statement-size limitation, at the SQL parser's internal stack rather than the interactive tool's buffer allocation.
• -801 — "SQL Edit buffer is full." A related interactive-editor memory limit, from accumulating multiple statements rather than one oversized one.

Shorten the statement (the same techniques as -762) or split it into parts, per the official guidance.