Informix Error -873

Reasons / Common Causes

-873 fires when a fragmentation expression references a column from a table other than the one being fragmented — per the official guidance, columns from different tables can't be mixed into a single fragment expression.

1. A fragmentation expression accidentally referencing a column from a different table — per the official guidance, the direct, only cause.
2. A copy-pasted fragmentation expression from a similar table's DDL, carrying over a column reference that doesn't exist (or means something different) on the table actually being fragmented.

Solutions / Resolution

1. Review the fragmentation expression's column references, confirming each one belongs to the table actually being fragmented.
2. Correct any reference to a column from a different table, replacing it with the equivalent column (or a derived value) on the current table.

Examples

The disallowed cross-table reference

CREATE TABLE order_items (item_id INT, order_id INT)
  FRAGMENT BY EXPRESSION
  (orders.region = 'east') IN dbspace1, REMAINDER IN dbspace2;
-- -873: orders.region is a column on a different table

Corrected — a column on order_items itself

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

Diagnostic Checks

1. Check every column referenced in the fragmentation expression against the table's own column list, confirming none belong to a different table.

Related Errors / Related Topics

• -869 — "Subqueries and procedures are not allowed in fragmentation expressions." A related fragmentation-expression restriction, about disallowed expression types rather than a cross-table column reference.
• -872 — "Invalid fragment strategy or expression for the unique index." A related restriction, about a unique index's expression referencing a column outside its own key columns (on the same table), rather than a different table entirely.

A fragmentation expression can only reference the table's own columns — check for an accidental cross-table reference.