Informix Error -860

Reasons / Common Causes

-860 fires when a fragmentation definition doesn't meet the minimum fragment count for its method — per the official guidance, round-robin and expression-based fragmentation each require at least two fragments; every other fragmentation method requires at least one.

1. A round-robin or expression-based fragmentation specification with only one fragment, per the official guidance — these two methods specifically require at least two.
2. A fragmentation specification accidentally reduced to zero fragments (all removed during editing), for a method requiring at least one.

Solutions / Resolution

1. Add at least a second fragment, per the official guidance, if the fragmentation method is round-robin or expression-based.
2. Add at least one fragment, per the official guidance, for any other fragmentation method with none specified.
3. Reconsider whether fragmentation is genuinely needed if only one storage location is actually intended — a single-fragment (or unfragmented) table doesn't need round-robin/expression-based fragmentation syntax at all.

Examples

Round-robin with only one fragment

CREATE TABLE orders (order_id INT) FRAGMENT BY ROUND ROBIN IN dbspace1;
-- -860: round-robin fragmentation requires at least two fragments

Corrected

CREATE TABLE orders (order_id INT) FRAGMENT BY ROUND ROBIN IN dbspace1, dbspace2;

Diagnostic Checks

1. Count the fragments in the specification against the minimum for its specific method (two for round-robin/expression-based, one for others).

Related Errors / Related Topics

• -773 — "Expression required for new fragment." A related fragmentation-specification error, about a missing expression rather than an insufficient fragment count.
• -774 — "Cannot specify fragment expressions with a round-robin fragmentation." A related fragmentation restriction, about round-robin's own expression rule.

Round-robin and expression-based fragmentation need at least two fragments; every other method needs at least one.