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Informix Error -624: Unable to drop CONSTRAINT constraint-name.

Cause and resolution

Unable to drop CONSTRAINT constraint-name.

This internal error shows that the database server had an unexpected error while dropping a constraint or the index that implemented it. Check the accompanying ISAM error code for more information. Corruption of the system catalogs or the root dbspace might have occurred, or a hardware problem might exist. If the error recurs, note all circumstances and contact IBM Informix Technical Support.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-624 is flagged by the official text as an internal error: the server hit an unexpected error while dropping a constraint or the index implementing it — per the official guidance, possibly reflecting corruption of the system catalogs or the root dbspace, or a hardware problem, the same general family as -620/-621/-622.

  1. System-catalog corruption, per the official guidance.
  2. Root dbspace corruption, per the official guidance.
  3. A hardware problem, per the official guidance, underlying either form of corruption.
  4. An underlying ISAM-level error during the drop, per the official guidance's pointer to checking the accompanying ISAM error code.
Solutions / Resolution
  1. Check the accompanying ISAM error code, per the official guidance, for the specific underlying reason.
  2. Have the database server administrator check for system-catalog or root dbspace corruption, using the same diagnostic path as -620/-622 (oncheck/onutil/tbcheck).
  3. Check for hardware errors, per the official guidance, via OS-level hardware/disk logs.
  4. If this recurs, note all circumstances and contact IBM Informix Technical Support, per the official guidance.
Examples
Checking for catalog/root dbspace corruption
$ oncheck -cc
-- or the platform-appropriate equivalent, given the constraint-drop failure
Diagnostic Checks
  1. Check the accompanying ISAM error code first, per the official guidance.
  2. Run a catalog/root dbspace consistency check, given the official guidance's framing around system-catalog or root dbspace corruption.
Related Errors / Related Topics
  • -620 — "Unable to update next extent size." Same general family of internal errors pointing at possible root dbspace corruption.
  • -621 — "Unable to update new lock level." Same family, pointing at hardware/shared-memory problems.
  • -622 — "Error on locating constraint index index-name." Same family, and the closest relative — also about locating/operating on a constraint's index under possible catalog/root dbspace corruption.

Same corruption-diagnosis path as -620/-622 — check the accompanying ISAM error, then run a catalog/root dbspace consistency check.