Informix Error -247

Reasons / Common Causes

-247 is closely related to -177's logical restore, but specifically about applying an audit trail to roll a database forward — the accompanying ISAM error code carries the specific cause.

1. Missing or corrupted audit trail records needed to complete the rollforward, the same general theme as -177's log-completeness requirement.
2. A gap in the audit trail sequence — a period during which the audit trail was disabled or dropped (see -133's topic) that rollforward can't bridge.
3. General media or corruption issues affecting the audit trail records themselves.

Solutions / Resolution

1. Check the accompanying ISAM error code, per the official guidance, for the specific underlying cause.
2. Verify the audit trail records needed for rollforward are complete and accessible, the same completeness check -177 recommends for logical restore's log requirements.
3. If a gap is found — a period where the audit trail was disabled — understand that rollforward genuinely can't bridge that specific gap; the recovery target may need to be adjusted to what's actually reconstructable.
4. Treat this with the same urgency as -176/-177 — rollforward is part of an active recovery effort, not routine maintenance.

Examples

Checking the accompanying code first

-- The specific ISAM error code accompanying -247 determines the fix —
-- check it before assuming a specific gap or corruption scenario

A gap from disabled audit trail

-- If the audit trail was disabled for a period (see -133), rollforward
-- can't reconstruct changes made during that window — the achievable
-- recovery point may need to be adjusted accordingly

Diagnostic Checks

1. Capture and review the accompanying ISAM error code.
2. Inventory the audit trail records needed for the rollforward and confirm completeness.
3. Check for any period where the audit trail was disabled, if a gap is suspected.

Related Errors / Related Topics

• -177 — "ISAM error: An error has occurred during logical restore." The closest structural sibling — the same general concept (reconstructing forward from a point-in-time baseline), applied to logical log replay rather than an audit trail specifically.
• -133 — "ISAM error: audit trail exists." Relevant if an audit-trail-disabled gap is the underlying cause.

Check for a gap in the audit trail sequence first — that's the most likely explanation if the accompanying ISAM error code doesn't point at straightforward corruption.