LICENSE

Copyright [1999-2015] Wellcome Trust Sanger Institute and the EMBL-European Bioinformatics Institute Copyright [2016-2024] EMBL-European Bioinformatics Institute

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

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NAME

Bio::EnsEMBL::DBSQL::ProxyDBConnection - Database connection wrapper allowing for one backing connection to be used for multiple DBs

SYNOPSIS

  my $dbc = Bio::EnsEMBL::DBSQL::DBConnection->new(-HOST => 'host', -PORT => 3306, -USER => 'user');
  my $p_h_dbc = Bio::EnsEMBL::DBSQL::ProxyDBConnection->new(-DBC => $dbc, -DBNAME => 'human');
  my $p_m_dbc = Bio::EnsEMBL::DBSQL::ProxyDBConnection->new(-DBC => $dbc, -DBNAME => 'mouse');
  
  # With a 10 minute timeout reconnection in milliseconds
  my $p_h_rc_dbc = Bio::EnsEMBL::DBSQL::ProxyDBConnection->new(-DBC => $dbc, -DBNAME => 'human', -RECONNECT_INTERVAL => (10*60*1000));

DESCRIPTION

This class is used to maintain one active connection to a database whilst it appears to be working against multiple schemas. It does this by checking the currently connected database before performing any query which could require a database change such as prepare.

This class is only intended for internal use so please do not use unless you are aware of what it will do and what the consequences of its usage are.

METHODS

switch_database

  Description : Performs a switch of the backing DBConnection if the currently
                connected database is not the same as the database this proxy
                wants to connect to. It currently supports MySQL, Oracle and
                Postges switches is untested with all bar MySQL. If it
                cannot do a live DB/schema switch then it will disconnect
                the connection and then wait for the next process to
                connect therefore switching the DB.
  Exceptions  : None but will warn if you attempt to switch a DB with 
                active kids attached to the proxied database handle.

check_reconnection

  Description : Looks to see if the last time we used the backing DBI
                connection was greater than the reconnect_interval()
                provided at construction or runtime. If enought time has 
                elapsed then a reconnection is attempted. We do not
                attempt a reconnection if:
                
                  - No reconnect_interval was set
                  - The connection was not active
                
  Exceptions  : None apart from those raised from the reconnect() method
                from DBConnection

reconnect_interval

        Arg[1]      : Integer reconnection interval in milliseconds
  Description : Accessor for the reconnection interval expressed in milliseconds
  Returntype  : Int miliseconds for a reconnection interval

dbname

        Arg[1]      : String DB name
  Description : Accessor for the name of the database we should use whenever
                a DBConnection request is made via this class
  Returntype  : String the name of the database which we should use
  Exceptions  : None