snmpa_local_db(3)

snmpa_local_db(3erl)       Erlang Module Definition       snmpa_local_db(3erl)

NAME
       snmpa_local_db - The SNMP built-in database

DESCRIPTION
       The  module  snmpa_local_db  contains functions for implementing tables
       (and variables) using the SNMP built-in database. The  database  exists
       in  two  instances, one volatile and one persistent. The volatile data-
       base is implemented with ets. The persistent  database  is  implemented
       with dets.

       There is a scaling problem with this database.

         * Insertions and deletions are inefficient for large tables.

       This problem is best solved by using Mnesia instead.

       The  following functions describe the interface to snmpa_local_db. Each
       function has a Mnesia equivalent. The argument NameDb is a tuple {Name,
       Db}  where  Name is the symbolic name of the managed object (as defined
       in the MIB), and Db is either volatile or  persistent.  mnesia  is  not
       possible since all these functions are snmpa_local_db specific.

COMMON DATA TYPES
       In the functions defined below, the following types are used:

         * NameDb = {Name, Db}

         * Name = atom(), Db = volatile | persistent

         * RowIndex = [int()]

         * Cols = [Col] | [{Col, Value}], Col = int(), Value = term()

       where RowIndex denotes the last part of the OID, that specifies the in-
       dex of the row in the table. Cols is a list of column numbers  in  case
       of  a get operation, and a list of column numbers and values in case of
       a set operation.

EXPORTS
       dump() -> ok | {error, Reason}

              Types:

                 Reason = term()

              This function can be used to manually dump the database to file.

       match(NameDb, Pattern)

              Performs an ets/dets matching on the table. See Stdlib  documen-
              tation,  module ets, for a description of Pattern and the return
              values.

       print()
       print(TableName)
       print(TableName, Db)

              Types:

                 TableName = atom()

              Prints the contents of the database on screen.  This  is  useful
              for  debugging  since  the  STANDARD-MIB and OTP-SNMPEA-MIB (and
              maybe your own MIBs) are stored in snmpa_local_db.

              TableName is an atom for a table in the database. When  no  name
              is supplied, the whole database is shown.

       table_create(NameDb) -> bool()

              Creates a table. If the table already exist, the old copy is de-
              stroyed.

              Returns false if the NameDb argument is  incorrectly  specified,
              true otherwise.

       table_create_row(NameDb, RowIndex, Row) -> bool()

              Types:

                 Row = {Val1, Val2, ..., ValN}
                 Val1 = Val2 = ... = ValN = term()

              Creates  a  row  in  a table. Row is a tuple with values for all
              columns, including the index columns.

       table_delete(NameDb) -> void()

              Deletes a table.

       table_delete_row(NameDb, RowIndex) -> bool()

              Deletes the row in the table.

       table_exists(NameDb) -> bool()

              Checks if a table exists.

       table_get_row(NameDb, RowIndex) -> Row | undefined

              Types:

                 Row = {Val1, Val2, ..., ValN}
                 Val1 = Val2 = ... = ValN = term()

              Row is a tuple with values for all columns, including the  index
              columns.

SEE ALSO
       ets(3erl), dets(3erl), snmp_generic(3erl)

Ericsson AB                        snmp 5.6               snmpa_local_db(3erl)