What causes "File name too long"?

Table name exceeds 63 bytes (most common when combining long table + column names) Column name exceeds 63 bytes individually Generated sequence names like tablename_columnname_seq exceed 63 bytes when combined

Is the "File name too long" error serious?

It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.

How to fix File name too long in PostgreSQL

PostgreSQLINTERMEDIATEMEDIUMUpdated Dec 28, 2025· 140 views

PostgreSQL encounters file name limits when identifiers exceed 63 bytes. This typically affects table names, column names, or auto-generated sequence names. Shortening identifiers to comply with PostgreSQL's naming constraints resolves the issue.

Quick fix

Fixes File name too long

-- BAD: 76 bytes
CREATE TABLE user_authentication_permission_settings (
  user_authentication_permission_settings_id SERIAL
);

-- GOOD: 42 bytes
CREATE TABLE user_auth_perm_settings (
  id SERIAL
);

Identify which identifier is too long
Shorten the problematic identifier
Explicitly name sequences and constraints
Update application code references

postgresql — error

$-- BAD: 76 bytes
CREATE TABLE user_authentication_permission_settings (
  user_authentication_permission_settings_id SERIAL
);
-- GOOD: 42 bytes
CREATE TABLE user_auth_perm_settings (
  id SERIAL
);
File name too long

What this error means

PostgreSQL enforces a strict 63-byte limit for all identifiers, including table names, column names, indexes, sequences, databases, and users. When PostgreSQL attempts to create or reference an identifier exceeding this limit, it raises a "file name too long" error, typically with SQL state code 58P03 (ERRCODE_FILE_NAME_TOO_LONG). This is a filesystem-level constraint inherited from PostgreSQL's internal naming mechanism. In some cases, PostgreSQL may silently truncate identifiers instead of raising an error, which can cause subtle bugs where references fail to match the truncated identifier.

Typical symptoms

Creating tables or columns with long names fails with "file name too long"
Auto-generated sequences from SERIAL columns fail when table and column names are long
Column aliases in queries are truncated, breaking ORM mappings
Foreign key constraints reference mismatches due to truncated names
pgAdmin4 or other tools show session file errors with long identifiers

Common causes

Table name exceeds 63 bytes (most common when combining long table + column names)
Column name exceeds 63 bytes individually
Generated sequence names like `tablename_columnname_seq` exceed 63 bytes when combined
Constraint names (primary key, foreign key, unique) exceed 63 bytes
Multi-byte UTF-8 characters counted as multiple bytes push identifier over limit

How to fix "File name too long"

1Identify which identifier is too long

When PostgreSQL raises the error, check the error message for context. If not clear, review your CREATE TABLE, CREATE INDEX, or ALTER TABLE statement. Count the bytes of each identifier—remember that multi-byte UTF-8 characters count as multiple bytes (e.g., é counts as 2 bytes). Use SELECT length(identifier_name) if analyzing existing identifiers.

2Shorten the problematic identifier

Rename the table, column, or constraint to be 63 bytes or fewer. Use abbreviations or remove redundant words. For example:

sql

-- BAD: 76 bytes
CREATE TABLE user_authentication_permission_settings (
  user_authentication_permission_settings_id SERIAL
);

-- GOOD: 42 bytes
CREATE TABLE user_auth_perm_settings (
  id SERIAL
);

3Explicitly name sequences and constraints

If auto-generated names fail, specify shorter custom names:

sql

CREATE TABLE user_profiles (
  id SERIAL,
  email VARCHAR(255) NOT NULL,
  CONSTRAINT uc_user_email UNIQUE (email),
  CONSTRAINT pk_user_profiles PRIMARY KEY (id)
);

-- Or explicitly create the sequence
CREATE SEQUENCE user_profiles_id_seq;
ALTER TABLE user_profiles ALTER COLUMN id SET DEFAULT nextval('user_profiles_id_seq');

4Update application code references

Update your ORM mappings, SQL queries, and column aliases to use the new shorter names:

typescript

// TypeORM example
@Entity('user_auth_perm_settings')
export class UserAuthPermSettings {
  @PrimaryGeneratedColumn()
  id: number;
}

// Prisma example
model user_auth_perm_settings {
  id    Int     @id @default(autoincrement())
}

5Test with long identifiers in lowercase

PostgreSQL applies the 63-byte limit uniformly. Use lowercase identifiers where possible, as quoted identifiers preserve case and may be longer in some contexts. If you must use long names, consider whether the naming convention is necessary.

Advanced notes

PostgreSQL's 63-byte identifier limit is hardcoded via the NAMEDATALEN constant in the C source code. While it can be increased when compiling PostgreSQL from source (e.g., to 256 bytes), the PostgreSQL community has resisted making it a configurable default due to storage and performance implications. When combined identifiers exceed the limit, PostgreSQL silently truncates them in some operations, leading to difficult-to-debug issues where references fail. In TypeORM and similar ORMs, this manifests as column aliases being truncated in SELECT statements, causing the ORM to fail mapping results. Always keep identifier names concise and use consistent abbreviation patterns across your schema to avoid surprises when combining names programmatically.

Frequently asked questions

What does "File name too long" mean?: PostgreSQL enforces a strict 63-byte limit for all identifiers, including table names, column names, indexes, sequences, databases, and users. When PostgreSQL attempts to create or reference an identifier exceeding this limit, it raises a "file name too long" error, typically with SQL state code 58P03 (ERRCODE_FILE_NAME_TOO_LONG). This is a filesystem-level constraint inherited from PostgreSQL's internal naming mechanism.
How do I fix "File name too long"?: PostgreSQL encounters file name limits when identifiers exceed 63 bytes. This typically affects table names, column names, or auto-generated sequence names. Shortening identifiers to comply with PostgreSQL's naming constraints resolves the issue.
What causes "File name too long"?: Table name exceeds 63 bytes (most common when combining long table + column names) Column name exceeds 63 bytes individually Generated sequence names like tablename_columnname_seq exceed 63 bytes when combined
Is the "File name too long" error serious?: It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.