max_identifier_length

A preset configuration parameter reporting the maximum length of object identifiers

max_identifier_length is a preset configuration parameter reporting the maximum length of object identifiers for the database instance.

max_identifier_length was added in PostgreSQL 8.0.

Usage

max_identifier_length reports the value of NAMEDATALEN - 1, which will be 63 unless NAMEDATALEN was changed at compile time.

It is not possible to modify max_identifier_length (or change the NAMEDATALEN value by any other means). See the NAMEDATALEN entry for further details.

Change history

Examples

postgres=# SHOW max_identifier_length;
 max_identifier_length
-----------------------
 63
(1 row)

It is not possible to modify the value of max_identifier_length:

postgres=# ALTER SYSTEM SET max_identifier_length = 128;
ERROR:  parameter "max_identifier_length" cannot be changed

Categories

GUC configuration item, PostgreSQL internals, Preset configuration item