HV091ERRORTier 2 — Caution✅ HIGH confidence

fdw_invalid_descriptor_field_identifier

Category: Foreign Data Wrapper ErrorVersions: PostgreSQL 9.1+

What this means

A foreign data wrapper used an invalid identifier to access a descriptor field, indicating an internal FDW implementation error in descriptor field access.

Why it happens

1FDW code accessed a descriptor field using an unrecognised or invalid field identifier
2Descriptor field identifier is out of range for the descriptor type
3FDW implementation uses a hard-coded field ID that does not match the current PostgreSQL version

How to reproduce

Internal FDW descriptor field access during query planning or execution

trigger — this will ERROR

SELECT * FROM my_foreign_table;

ERROR: HV091: fdw_invalid_descriptor_field_identifier

Fix 1: Update the FDW to a version compatible with your PostgreSQL version

Descriptor field identifier mismatch after PostgreSQL upgrade

fix

ALTER EXTENSION my_fdw UPDATE;

Why this works

Ensures FDW uses correct descriptor field identifiers for the installed PostgreSQL version

What not to do

✗

Do not hard-code descriptor field IDs in custom FDW implementations

Why it's wrong: Field IDs can change across PostgreSQL versions; use the defined constants

Sources

📚 Official docs: https://www.postgresql.org/docs/current/fdw-callbacks.html

🔧 Source ref: https://www.postgresql.org/docs/current/errcodes-appendix.html

Confidence assessment

✅ HIGH confidence

Standard FDW error code from official PostgreSQL appendix.