Informix Error -897

Reasons / Common Causes

-897 fires when ALTER TABLE or DROP TABLE targets a table that's currently serving as a violations table or diagnostics table for another table — per the official guidance, these tables are managed by the violations/diagnostics mechanism itself and can't be altered or dropped directly.

1. ALTER TABLE/DROP TABLE targeting a table currently serving as a violations table, per the official guidance.
2. ALTER TABLE/DROP TABLE targeting a table currently serving as a diagnostics table, per the official guidance.

Solutions / Resolution

1. Stop the violations table relationship first, via STOP VIOLATIONS TABLE on the target table these tables belong to, per -896's discussion:

   STOP VIOLATIONS TABLE FOR orders;
   

2. Then alter or drop the (now-independent) former violations/diagnostics table, once it's no longer serving in that role.
3. Identify which target table a given violations/diagnostics table belongs to, if it's not obvious, before attempting STOP VIOLATIONS TABLE.

Examples

Stopping the violations table relationship before dropping it

STOP VIOLATIONS TABLE FOR orders;
DROP TABLE orders_viol;

Diagnostic Checks

1. Confirm whether the table being altered/dropped is currently serving as a violations/diagnostics table, and if so, identify the target table it belongs to.

Related Errors / Related Topics

• -895 — "Cannot create violations/diagnostics table." A related error, about failing to create one, rather than being unable to modify/drop an existing one.
• -898 — "Cannot alter a table which has associated violations/diagnostics tables." The mirror-image restriction: altering the target table itself, rather than its violations/diagnostics table.

Stop the violations table relationship first (STOP VIOLATIONS TABLE), then alter or drop the now-independent table.