HP-UX Reference (11i v2 04/09) - 3 Library Functions N-Z (vol 7)

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nis_db(3N) nis_db(3N)

with numattrs number of elements.

db_remove_entry()

removes all entries that satisfy the given attributes.

db_free_result() can

be used to free up the returned

db_result structure. attrs is an array of nis_attr structure with

numattrs number of elements.

db_add_entry()

adds a copy of the given object to the speciﬁed table, replacing the one identiﬁed by

the given attributes. If the given attributes identify more than one object,

DB_NOTUNIQUE is returned.

If no object is identiﬁed by the given attributes, the object is added.

attrs is an array of nis_attr

structure with numattrs number of elements. db_free_result()

can be used to free up the returned

db_result structure.

db_table_exists()

provides an efﬁcient way for the NIS+ service to detect that a table exists. This

increases response time to the client and lowers the load on the server.

db_unload_table()

is used by the service to unload or deactivate tables that are not currently being

used. The service internally keeps track of access patterns to tables and will unload those tables that

have not been accessed for a while. By unloading infrequently accessed tables, the service can minimize

the amount of system resources for efﬁcient operation.

db_checkpoint()

organizes the contents of the table in a more efﬁcient manner. Checkpointing may

mean different things to different types of databases. It does not affect the logical contents of the table —

operations and queries should return the same result before and after a checkpoint. For example, in a

log-based system, checkpointing may mean incorporating log entries of updates accumulated since the

previous checkpoint into the table.

db_free_result()

frees up the space allocated by various functions listed on this manual page that

return a

db_result structure.

db_standby() is an advisory call to the database manager. This call informs the database that

activity has slowed down and it can free up unnecessary resources such as ﬁle descriptors.

MULTITHREAD USAGE

Thread Safe: No

Cancel Safe: No

Fork Safe: No

Async-cancel Safe: No

Async-signal Safe: No

These functions can not be called safely in a multithreaded environment.

PROGRAMMING

Most of the routines in this library use an NIS+ name to identify the object that the user desires. The

name must be in canonical form before being passed to the database because one server may be serving

several namespaces and discrimination of the requested objects is accomplished by comparing the domain

names.

WARNINGS

HP-UX 11i Version 2 is the last HP-UX release on which NIS+ is supported.

LDAP is the recommended replacement for NIS+. HP fully supports the industry standard naming ser-

vices based on LDAP.

DIAGNOSTICS

DB_SUCCESS The query or operation completed successfully and returned status.

DB_NOTFOUND The name or entry that was named in the argument did not exist.

DB_NOTUNIQUE An attempt was made to remove an entry from a table that is not uniquely speciﬁed.

DB_BADQUERY The query that was submitted to the database was invalid (for example, it might

name some nonexistent ﬁelds).

DB_BADTABLE The table was corrupted.

DB_BADOBJECT The ﬁelds of the object does not conform to the ﬁelds of the table to which it is being

added.

DB_MEMORY_LIMIT

There is insufﬁcient memory to complete the operation requested.

HP-UX 11i Version 2: September 2004 − 3 − Hewlett-Packard Company Section 3−−657