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
       database 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 index 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  documentation,  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 destroyed.

              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)