Informix Error -779: Duplicate table name in the alter fragment specification.

Reasons / Common Causes

-779 fires when an ALTER FRAGMENT ... ATTACH specification names the same table more than once — per the official guidance, a table can only be attached once per statement.

1. The same table name accidentally repeated in the ATTACH list — the direct, only cause.
2. A generated list of tables to attach (for example, one table per partition being merged in) that wasn't deduplicated before being used in the statement.

Solutions / Resolution

1. Check that the alter fragment specification attaches the same table only once, per the official guidance.
2. Review the full attach list carefully if the duplication isn't among the first few entries.

Examples

The disallowed duplicate

ALTER FRAGMENT ON TABLE orders ATTACH orders_2025, orders_2024, orders_2025;
-- -779: orders_2025 listed twice

Corrected

ALTER FRAGMENT ON TABLE orders ATTACH orders_2025, orders_2024;

Diagnostic Checks

1. Scan the ATTACH list for a repeated table name.

Related Errors / Related Topics

• -782 — "Attached table is fragmented." A related ATTACH restriction, about the attached table's own structure rather than duplication in the attach list.

A straightforward duplicate in the ATTACH list — scan for the repeated table name.