SQLSTATE HV00B signals that a foreign data wrapper returned or is using an invalid internal handle.
fdw_invalid_handle (SQLSTATE HV00B) means PostgreSQL received an invalid or stale handle from a foreign data wrapper. Restart the session, refresh or recreate the foreign server or extension, and ensure version compatibility to clear the error.
fdw_invalid_handle
PostgreSQL raises fdw_invalid_handle (SQLSTATE HV00B) when a foreign data wrapper (FDW) returns a NULL, stale, or otherwise unusable pointer to an underlying remote resource. The core planner or executor cannot dereference that pointer, so query execution aborts.
The error appears during SELECT, INSERT, UPDATE, or ANALYZE operations on foreign tables that rely on an FDW such as postgres_fdw, mysql_fdw, or oracle_fdw.
Because the handle is invalid at runtime, the operation cannot proceed and the backend exits with the HV00B condition.
An invalid handle usually stems from a dropped or closed remote cursor, a broken network link, or an FDW extension compiled against a different PostgreSQL version.
Memory corruption or mishandled state inside custom FDWs can also produce null handles.
Long-running sessions intensify the risk because remote connections may time out or be closed by firewalls, leaving the FDW with a dangling reference when the next statement executes.
Start with the simplest step: close the current session and reconnect. This forces the FDW to obtain fresh handles for remote objects. If the error persists, restart the foreign server with ALTER SERVER ...
OPTIONS (fdw_startup_cost 0); or by dropping and recreating the server.
Verify that the FDW extension version matches the PostgreSQL server version. Reinstall or recompile the extension if a mismatch exists. Finally, examine server logs for segmentation faults inside the FDW and update to a maintained release if needed.
Running ANALYZE on a foreign table after the remote DBA terminated the underlying session triggers fdw_invalid_handle.
Solution: REFRESH CONNECTION or reconnect.
Executing a prepared statement on a foreign table after an HA failover on the remote database produces stale handles. Solution: DISCARD ALL or reconnect, then re-prepare the statement.
Keep FDW extensions patched and compiled against your PostgreSQL major release.
Automate extension updates during server upgrades.
Use shorter idle-in-transaction timeouts and TCP keepalives to prevent network devices from silently dropping long-lived connections.
fdw_unable_to_create_reply (HV00J) surfaces when the FDW cannot allocate memory for a reply message. The troubleshooting steps mirror fdw_invalid_handle: patch, reconnect, and verify extension compatibility.
connection_does_not_exist (08003) appears when the server references a closed connection. Reconnect or restart foreign servers to resolve.
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The FDW callback returned a NULL or garbage pointer because of internal logic errors or memory corruption.
A remote cursor or connection was closed by the foreign server or a firewall, leaving the FDW with a dangling handle.
The FDW binary was compiled for a different PostgreSQL version, leading to incompatible internal structures.
Administrators dropped or altered foreign tables, servers, or user mappings while active sessions still referenced them.
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No. Even in development, ignoring it masks problems in your FDW configuration or versioning that will surface in production.
Restarting clears in-memory handles and often fixes the issue, but the root cause may persist if the FDW binary is incompatible.
Galaxy’s session management detects broken connections and prompts an automatic reconnect before query execution, reducing the chance of invalid FDW handles.
No. Any FDW that mishandles internal pointers can raise fdw_invalid_handle, including mysql_fdw and oracle_fdw.
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