How to diagnose and fix the 42622 name_too_long error code in Postgres.

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The 42622 error code in PostgreSQL indicates that an identifier is too long. PostgreSQL enforces a maximum length for identifiers, which is 63 bytes. Identifiers include names of tables, columns, indexes, sequences, databases, users, and other PostgreSQL objects. If you try to create or reference an identifier with more than 63 bytes, PostgreSQL will raise this error.

Here’s how to diagnose and fix the 42622 error code:

Diagnosis:

  1. Check the logs or error messages to identify which identifier is causing the issue.
  2. Count the number of characters in the identifier. Remember that a multi-byte character counts as multiple bytes.

Fix:

To resolve this issue, you’ll need to shorten the identifier to 63 bytes or less. Here are some examples:

Example 1: Creating a table with a long name

-- This will cause an error
CREATE TABLE this_is_a_very_long_table_name_that_will_cause_an_error_because_it_is_too_long();

-- To fix it, shorten the table name
CREATE TABLE shortened_table_name();

Example 2: Creating an index with a long name

-- This will cause an error
CREATE INDEX this_is_a_very_long_index_name_that_will_cause_an_error_because_it_is_too_long ON my_table (my_column);

-- To fix it, shorten the index name
CREATE INDEX shortened_index_name ON my_table (my_column);

Example 3: Creating a column with a long name

-- This will cause an error
ALTER TABLE my_table ADD COLUMN this_is_a_very_long_column_name_that_will_cause_an_error_because_it_is_too_long VARCHAR(255);

-- To fix it, shorten the column name
ALTER TABLE my_table ADD COLUMN shortened_col_name VARCHAR(255);

Considerations:

  • If you have scripts or application code that reference the long identifier, you’ll need to update those references to match the new shortened name.
  • If the long identifier is already in use and you can’t change it, you may need to create an alias or use a shortened version of the name in your queries.
  • When designing your database schema, it’s a good practice to choose concise, yet descriptive, names for identifiers to avoid this issue.

Remember, the key to fixing the 42622 error is to ensure that all identifiers are within the 63-byte limit imposed by PostgreSQL, as stated in the PostgreSQL Error Codes documentation.

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