Identifiers should adhere to the following restrictions:
  1. All identifiers except for user name and index name should be between 1 and up to 127 characters long.
  2. User names should be between 1 and up to 64 characters long.
  3. Index names should be between 1 and up to 264 characters long.
  4. Begin with a letter (a-z or A-Z) or an underscore (_).
  5. Subsequent characters can be letters, underscores, digits (0-9), or dollar signs ($).
  6. Unsupported characters or reserved words are permitted only if they are surrounded by double quotes. An exception to that rule is that a reserved word can be used as a user_name (because user names are not used as part of SQL statements).
  7. Names are case-sensitive. However, unquoted names are always converted to lowercase, and quoted names preserve the case and also allow spaces within the names. For example: CAMEL, Camel, camel and “camel” all refer to the same name (camel). On the other hand, “CAMEL”, “Camel” and “camel” refer to three different names.