Informix Error -858: Cannot specify the same partition/space name twice in a fragmentation specification.

Reasons / Common Causes

-858 fires when a fragmentation specification (in CREATE TABLE, CREATE INDEX, or ALTER FRAGMENT) names the same dbspace or partition more than once — per the official guidance, each fragment must use a distinct dbspace/partition name.

1. The same dbspace name accidentally repeated across two fragment definitions, per the official guidance — the direct, common cause.
2. A generated fragmentation specification (one fragment per category/range, built programmatically) that wasn't deduplicated before being used.

Solutions / Resolution

1. Change the fragmentation specification to use different dbspaces/partitions for each fragment, per the official guidance.
2. Review the full specification carefully if the duplication isn't among the first few fragments, since it can appear anywhere in a longer list.

Examples

The disallowed duplicate

CREATE TABLE orders (order_id INT, region CHAR(10))
  FRAGMENT BY EXPRESSION
  (region = 'east') IN dbspace1,
  (region = 'west') IN dbspace1;
-- -858: dbspace1 used twice

Corrected

CREATE TABLE orders (order_id INT, region CHAR(10))
  FRAGMENT BY EXPRESSION
  (region = 'east') IN dbspace1,
  (region = 'west') IN dbspace2;

Diagnostic Checks

1. Scan the fragmentation specification's dbspace/partition names for a repeated entry.

Related Errors / Related Topics

• -779 — "Duplicate table name in the alter fragment specification." A related duplication restriction, in the ATTACH clause's table list rather than a fragmentation specification's dbspace/partition names.

A straightforward duplicate dbspace/partition name — scan the specification for the repeated entry.