ODBC Server Reference Manual

Transact-SQL Language
HP NonStop ODBC Server Reference Manual—429151-002
4-10
Names
at connection time is used to qualify the object. If the database name is missing,
the default database indicated in the ZNSPROF profile record for the current
logical username is used.
Some additional considerations for alias usernames are as follows:
•
They can be used in place of their associated logical usernames for logging on.
•
They cannot be used for qualifying object names.
•
They are system-wide, not restricted to a given database.
•
If the owner name is missing from an object reference, the logical username
associated with the alias username is used.
The NonStop ODBC Server authenticates a logon username as follows:
1. NOSUTIL first checks the length of the logon username. If the name is longer than
17 characters, it cannot be a Guardian name, so NOSUTIL sets the corresponding
Guardian username (G_USERNAME) to NULL. If the name is 17 or fewer
characters, NOSUTIL does not set G_USERNAME.
2. The NonStop ODBC server then searches the username alias table, ZNSALT, for a
mapping entry for the logon username:
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If a mapping entry is found, the NonStop ODBC server determines the
PROFILE_NAME and NOS_USERNAME from the ZNSALT table and the
corresponding Guardian username (G_USERNAME) from the ZNSUS table.
The NonStop ODBC server uses this information and the corresponding
password to authenticate the user.
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If a mapping entry is not found, the NonStop ODBC server does not consider
the user to be an ODBC user. The NonStop ODBC server tries to authenticate
the user; however, even if the authentication is successful, the NonStop ODBC
server does not allow the user to perform DDL operations.
3. If the authentication fails and the logon username is 17 or fewer characters, the
NonStop ODBC server converts the name to a Guardian format name
(group.user) by substituting the first underscore with a period. The NonStop
ODBC server then tries to authenticate the user using the converted Guardian
name.
Note. If Safeguard is in effect for the system and the username is an alias, the NonStop
ODBC server always uses the alias name for the logon. If the username is not an alias, the
NonStop ODBC server uses the Guardian name for the logon. If Safeguard is not in effect, the
NonStop ODBC server always uses the Guardian name for the logon.