How to fix HV005: fdw_column_name_not_found in PostgreSQL

Use psql to describe the foreign table and compare its columns with the ones you expect to query.

-- Show the local column map and id, fdw_column_name options:
\d+ foreign_schema.remote_table

-- Or query the information schema for the FDW mapping:
SELECT column_name, foreign_column_name
FROM information_schema.foreign_table_columns
WHERE foreign_table_schema = 'foreign_schema'
  AND foreign_table_name = 'remote_table';

If the column mentioned in the HV005 error is listed here, PostgreSQL is trying to send it to the remote server even though the remote copy does not have it.

Connect directly to the remote server (or reuse the same server connection) and list the remote columns. This confirms whether the column exists and how it is spelled/cased.

\c - foreign_server_db
SELECT column_name
FROM information_schema.columns
WHERE table_schema = 'public'
  AND table_name = 'actual_table_name';

If the column is missing, you now know why FDW raised HV005; if it exists under another name, note the exact spelling.

Drop or rename the stale column on the foreign table, or add a new column that maps to the current remote column name. When you alter a foreign table, you can supply fdw_column_name so PostgreSQL knows the remote identifier.

ALTER FOREIGN TABLE foreign_schema.remote_table
  DROP COLUMN missing_column;

ALTER FOREIGN TABLE foreign_schema.remote_table
  ADD COLUMN new_column text
    OPTIONS (fdw_column_name 'real_remote_name');

If multiple columns changed, repeat this step until the local definition mirrors what the remote catalog reports.

When the remote table underwent wholesale changes, it can be easier to drop the foreign table and re-run IMPORT FOREIGN SCHEMA so PostgreSQL rebuilds the column list from scratch.

DROP FOREIGN TABLE IF EXISTS foreign_schema.remote_table;
IMPORT FOREIGN SCHEMA public
  LIMIT TO (remote_table)
  FROM SERVER remote_server
  INTO foreign_schema;

This always pulls the current column set. Remember to reapply any custom column-level options, permissions, or triggers afterward.