Some schema objects are made up of parts that you can or must name, such as the columns in a table or view, index and table partitions and subpartitions, integrity constraints on a table, and objects that are stored within a package, including procedures and stored functions. This section provides:
• Rules for naming schema objects and schema object location qualifiers
• Guidelines for naming schema objects and qualifiers
Schema Object Naming Rules
Every database object has a name. In a SQL statement, you represent the name of an object with a quoted identifier or a nonquoted identifier.
• A quoted identifier begins and ends with double quotation marks ("). If you name a schema object using a quoted identifier, then you must use the double quotation marks whenever you refer to that object.
• A nonquoted identifier is not surrounded by any punctuation.
You can use either quoted or nonquoted identifiers to name any database object, with one exception: database links must be named with nonquoted identifiers. In addition, Oracle strongly recommends that you not use quotation marks to make usernames and passwords case sensitive. Please refer to CREATE USER for additional rules for naming users and passwords.
The following list of rules applies to both quoted and nonquoted identifiers unless otherwise indicated:
1. Names must be from 1 to 30 bytes long with these exceptions:
• Names of databases are limited to 8 bytes.
• Names of database links can be as long as 128 bytes.
2. Nonquoted identifiers cannot be Oracle Database reserved words. Quoted identifiers can be reserved words, although this is not recommended.
Depending on the Oracle product you plan to use to access a database object, names might be further restricted by other product-specific reserved words.
Note:
The reserved word ROWID is an exception to this rule. You cannot use the uppercase word ROWID as a name, even in double quotation marks. However, you can use the word with one or more lower case letters (for example, "Rowid" or "rowid").
O treinamento "Oracle Database 10g: Administration Workshop I" diz que uma conta de usuário deve possuir um nome único de até 30 caracteres, excluindo caracteres especiais, e devem iniciar com uma letra. Senhas tbém devem iniciar com uma letra.