Identifiers

Identifiers (names) of objects such as tables, projections, users, etc., can be up to 63 bytes in length.

Unquoted Identifiers

Unquoted SQL identifiers must begin with one of the following:

• an alphabetic character (a-z including letters with diacritical marks and non-Latin letters)
• underscore (_)

Subsequent characters in an identifier can be:

• alphabetic
• numeric (0-9)
• dollar sign ($) (not allowed in identifiers according to the SQL standard and thus may cause application portability problems)

  Unquoted identifiers are not case-sensitive. Thus, the unquoted identifiers ABC, ABc, and aBc are synonymous.

Quoted Identifiers

Identifiers enclosed in double quote (") characters can contain any character other than a double quote itself. (To include a double quote, write two double quotes.) This allows you to use names that would otherwise be invalid, such as ones that include only numeric characters ("123" for example) or contain space characters, punctuation marks, keywords, etc.

Quoted identifiers are case-sensitive. Thus, the quoted identifiers "ABC", "ABc", and "aBc" are distinct.