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Informix Error -493

-493 DBNLS not set (LC_CTYPE must be string_value).

Set the DBNLS environment variable to an appropriate value. Make sure LC_TYPE is set to the specified string_value.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-493 is the LC_CTYPE counterpart of -491's LC_COLLATE requirement: the same underlying DBNLS-environment-configuration issue, but here the specific variable named in the error is LC_CTYPE (which governs character classification — what counts as a letter, digit, etc. — for the target locale), and the required value is stated directly in the message.

  1. DBNLS not set at all in the environment of the session/application connecting to an NLS-enabled database.
  2. LC_CTYPE set to a value that doesn't match what the database actually requires — the error message itself names the expected string_value.
  3. LC_COLLATE correctly configured (avoiding -491) but LC_CTYPE overlooked, since the two are configured independently.
Solutions / Resolution
  1. Configure the DBNLS environment variable appropriately, per the official guidance.
  2. Ensure LC_CTYPE is set to the specific string value named in the error message, per the official guidance.
  3. Check both LC_COLLATE and LC_CTYPE together when configuring environment variables for an NLS-enabled database — fixing one doesn't imply the other is also correct.
Examples
Setting DBNLS and LC_CTYPE
export DBNLS=1
export LC_CTYPE=en_us.utf8
-- use the exact value named in the error message
Diagnostic Checks
  1. Check whether DBNLS is set in the connecting session's environment.
  2. Check LC_CTYPE's current value against the specific string_value named in the error message.
Related Errors / Related Topics
  • -491 — "DBNLS not set (LC_COLLATE must be string_value)." The closely related sibling — the identical underlying issue, for LC_COLLATE instead of LC_CTYPE.
  • -492 — "LANG or LC_COLLATE environment variable invalid." A related NLS-environment error, about an invalid value rather than a missing one.

Check LC_COLLATE and LC_CTYPE together — resolving one of these NLS-environment errors doesn't guarantee the other variable is also correctly configured.