Informix Error -707

Reasons / Common Causes

-707 fires when CREATE OPTICAL CLUSTER's FOR clause names the same column more than once — per the official guidance, every column in the list must be distinct.

1. The same column name accidentally repeated in the FOR clause's column list — the direct, only cause.
2. A copy-pasted or generated column list that wasn't deduplicated before being used in the CREATE OPTICAL CLUSTER statement.

Solutions / Resolution

1. Change the statement so no column appears more than once, per the official guidance.
2. Review the full column list carefully if the duplication isn't among the first few entries.

Examples

The disallowed duplicate

CREATE OPTICAL CLUSTER doc_cluster FOR content_a, content_b, content_a ...;
-- -707: content_a listed twice

Corrected

CREATE OPTICAL CLUSTER doc_cluster FOR content_a, content_b ...;

Diagnostic Checks

1. Scan the FOR clause's column list for a repeated column name.

Related Errors / Related Topics

• -639 — "Cannot cluster TEXT or BYTE columns on different optical families." A related CREATE OPTICAL CLUSTER FOR-clause restriction, about column family membership rather than duplication.

A straightforward duplicate column in the FOR clause — scan for the repeated name.