information_schema.domains.character_octet_length

Note:

If the domain has a character type, the maximum possible length in octets (bytes) of a datum; null for all other data types. The maximum octet length depends on the declared character maximum length (see above) and the server encoding.

Note:

If the domain has a character type, the maximum possible length in octets (bytes) of a datum; null for all other data types. The maximum octet length depends on the declared character maximum length (see above) and the server encoding.

Note:

If the domain has a character type, the maximum possible length in octets (bytes) of a datum (this should not be of concern to PostgreSQL users); null for all other data types.

Note:

Maximum length, in bytes, for binary data, character data, or text and image data. -1 for xml and large-value type data. Otherwise, NULL is returned.