How to fix Name too long in PostgreSQL

PostgreSQLINTERMEDIATEMEDIUM

PostgreSQL enforces a 63-character maximum length for all identifiers (table names, column names, index names, etc.). When you exceed this limit, PostgreSQL truncates the identifier silently, which can cause duplicate name errors or missing references when your application expects the full name.

What this error means

PostgreSQL has a fundamental limit on identifier length: all identifiers (table names, column names, constraint names, index names, sequence names, database names, and more) are restricted to a maximum of 63 bytes. This limit is set by the NAMEDATALEN constant, which is hardcoded in PostgreSQL at compile time with a default value of 64 (allowing 63 usable characters plus a null terminator). When you try to create an identifier longer than 63 characters, PostgreSQL doesn't immediately reject it with an error. Instead, it silently truncates the identifier to 63 bytes and proceeds. This behavior creates a dangerous situation: your code references the full identifier name, but the database has stored it under a truncated name, leading to mismatches and errors later. The 42622 error code specifically indicates "name_too_long"—a diagnostic error that some tools, frameworks, and database drivers raise when they detect this condition and want to prevent the truncation.

How to fix "Name too long"

1Identify the problematic identifier

First, determine which identifier is causing the error. Check your recent migrations, schema changes, or ORM-generated code:

sql

-- Query PostgreSQL catalog to find truncated identifiers
SELECT
  tablename,
  indexname,
  LENGTH(indexname) as name_length
FROM pg_indexes
WHERE schemaname = 'public'
ORDER BY LENGTH(indexname) DESC;

-- Or for tables:
SELECT
  tablename,
  LENGTH(tablename) as name_length
FROM pg_tables
WHERE schemaname = 'public'
ORDER BY LENGTH(tablename) DESC;

Look for any identifiers at exactly 63 characters—that's a sign of truncation. Compare the truncated name in the error with what your code intended to create.

2Shorten the identifier name

The most straightforward fix is to rename the problematic identifier to be under 63 characters. Use a shorter, more concise name:

For table names:

sql

-- Before (too long):
CREATE TABLE customer_order_line_item_product_association (
  id SERIAL PRIMARY KEY
);

-- After (under 63 chars):
CREATE TABLE customer_order_items (
  id SERIAL PRIMARY KEY
);

For index names (explicit naming):

sql

-- Before (auto-generated, may be too long):
CREATE INDEX ON loan_application_status_message_template_groups(message_template_group_id);

-- After (explicitly named, short):
CREATE INDEX idx_loan_app_status_msg_tpl_grp ON loan_application_status_message_template_groups(message_template_group_id);

For column names:

sql

-- Before (too long):
ALTER TABLE users ADD COLUMN customer_lifetime_value_in_usd_currency NUMERIC;

-- After (shortened):
ALTER TABLE users ADD COLUMN customer_lifetime_value NUMERIC;

Count characters carefully; remember multi-byte UTF-8 characters count as multiple bytes.

3Use custom naming conventions in ORMs

If you're using an ORM (Sequelize, Django, Rails, etc.), configure it to use shorter naming conventions to avoid auto-generated names exceeding 63 characters:

Sequelize example:

javascript

// Set a custom naming strategy with shorter names
const sequelize = new Sequelize(database, username, password, {
  dialect: 'postgres',
  define: {
    underscored: true,
  },
  // Limit index names to avoid truncation
});

// Explicitly name foreign keys and indexes
const User = sequelize.define('user', {
  id: { type: DataTypes.INTEGER, primaryKey: true },
});

const Post = sequelize.define('post', {
  userId: {
    type: DataTypes.INTEGER,
    references: {
      model: 'users',
      key: 'id',
      name: 'fk_post_user'  // Explicit short name instead of auto-generated
    }
  }
});

Rails example:

ruby

create_table :loan_application_status_message_templates do |t|
  t.references :message_template_group, foreign_key: { name: 'fk_loan_msg_tpl' }
  # Instead of Rails auto-generating a long FK name
end

# Or add custom index names:
add_index :loan_application_status_messages,
          [:loan_id, :status_id],
          name: 'idx_loan_msgs_status'

4Drop and recreate the problematic object

Once you've determined the fix, drop the truncated object and recreate it with a shorter name:

sql

-- Drop the incorrectly named index (use the truncated name from error)
DROP INDEX IF EXISTS "index_loan_application_status_message_templat";

-- Recreate with proper, short name
CREATE INDEX idx_loan_status_msg_tpl ON loan_application_status_message_template_groups(message_template_group_id);

-- If it's a constraint:
ALTER TABLE orders DROP CONSTRAINT IF EXISTS "fk_order_status_message_template_group_id";
ALTER TABLE orders ADD CONSTRAINT fk_order_status_msg_tpl_grp
  FOREIGN KEY (message_template_group_id) REFERENCES message_template_groups(id);

Test the schema changes before running them in production.

5Run migrations again if using a migration tool

If the error occurred during ORM migrations, update your migration files with the new shorter names, then re-run the migrations:

bash

# For Rails:
rails db:rollback
# Edit the migration file to use short names
rails db:migrate

# For Sequelize:
npx sequelize-cli db:migrate:undo
# Edit the migration, use explicit short index names
npx sequelize-cli db:migrate

# For Prisma:
npx prisma migrate reset
# Update your schema.prisma with shorter names
npx prisma migrate dev --name fix_identifier_length

Ensure your naming strategy prevents this issue in future migrations.

How to fix Name too long in PostgreSQL

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How to fix "Name too long"

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