42622ERRORTier 2 — Caution✅ HIGH confidence

name too long

Category: Syntax Error or Access Rule ViolationVersions: All Postgres versions

What this means

SQLSTATE 42622 is raised when an identifier (table name, column name, constraint name, etc.) exceeds the maximum length allowed by Postgres. By default, the maximum identifier length is 63 bytes (NAMEDATALEN - 1).

Why it happens

1An identifier exceeds 63 bytes (the default NAMEDATALEN limit)
2Auto-generated constraint names (e.g., from long table and column name combinations) exceed 63 bytes

How to reproduce

Creating a column with a name exceeding 63 bytes.

trigger — this will ERROR

CREATE TABLE t (
  this_column_name_is_way_too_long_to_fit_in_the_postgres_name_limit_of_63_bytes TEXT
);

ERROR: identifier "this_column_name_is_way_too_long_to_fit_in_the_postgres_name_limit_of_63_bytes" will be truncated to "this_column_name_is_way_too_long_to_fit_in_the_postgres_na"

Fix 1: Shorten the identifier to 63 bytes or fewer

When creating long-named objects.

fix

CREATE TABLE t (
  long_description_column TEXT -- shortened
);

Why this works

Postgres silently truncates identifiers that are too long (with a warning). To avoid the truncation and potential name collisions, use explicitly shorter names.

Fix 2: Explicitly name auto-generated constraints with short names

When auto-generated constraint names may be too long.

fix

ALTER TABLE orders ADD CONSTRAINT fk_orders_cust
  FOREIGN KEY (customer_id) REFERENCES customers(id);

Why this works

Providing an explicit short constraint name prevents auto-generated names from being truncated in ways that may clash.

Version notes

All versionsNAMEDATALEN is a compile-time constant defaulting to 64 (max identifier = 63 bytes). Rebuilding Postgres from source with a higher NAMEDATALEN is possible but non-standard.

Sources

📚 Official docs: https://www.postgresql.org/docs/current/errcodes-appendix.html

🔧 Source ref: Class 42 — Syntax Error or Access Rule Violation

Confidence assessment

✅ HIGH confidence

Standard SQLSTATE. The 63-byte limit is consistent across all versions with default NAMEDATALEN.