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Bio::DB::GFF::Adaptor:User:ContribuoedDPerlFD::Adaptor::dbi::caching_handle(3)

NAME
       Bio::DB::GFF::Adaptor::dbi::caching_handle -- Cache for database
       handles

SYNOPSIS
	use Bio::DB::GFF::Adaptor::dbi::caching_handle;
	$db  = Bio::DB::GFF::Adaptor::dbi::caching_handle->new('dbi:mysql:test');
	$sth = $db->prepare('select * from foo');
	@h   = $sth->fetch_rowarray;
	$sth->finish

DESCRIPTION
       This module handles a pool of database handles.	It was motivated by
       the MYSQL driver's {mysql_use_result} attribute,	which dramatically
       improves	query speed and	memory usage, but forbids additional query
       statements from being evaluated while an	existing one is	in use.

       This module is a	plug-in	replacement for	vanilla	DBI.  It automatically
       activates the {mysql_use_result}	attribute for the mysql	driver,	but
       avoids problems with multiple active statement handlers by creating new
       database	handles	as needed.

USAGE
       The object constructor is
       Bio::DB::GFF::Adaptor::dbi::caching_handle->new().  This	is called like
       DBI->connect() and takes	the same arguments.  The returned object looks
       and acts	like a conventional database handle.

       In addition to all the standard DBI handle methods, this	package	adds
       the following:

   dbi_quote
	Title	: dbi_quote
	Usage	: $string = $db->dbi_quote($sql,@args)
	Function: perform bind variable	substitution
	Returns	: query	string
	Args	: the query string and bind arguments
	Status	: public

       This method replaces the	bind variable "?" in a SQL statement with
       appropriately quoted bind arguments.  It	is used	internally to handle
       drivers that don't support argument binding.

   do_query
	Title	: do_query
	Usage	: $sth = $db->do_query($query,@args)
	Function: perform a DBI	query
	Returns	: a statement handler
	Args	: query	string and list	of bind	arguments
	Status	: Public

       This method performs a DBI prepare() and	execute(), returning a
       statement handle.  You will typically call fetch() of fetchrow_array()
       on the statement	handle.	 The parsed statement handle is	cached for
       later use.

   debug
	Title	: debug
	Usage	: $debug = $db->debug([$debug])
	Function: activate debugging messages
	Returns	: current state	of flag
	Args	: optional new setting of flag
	Status	: public

   attribute
	Title	: attribute
	Usage	: $value = $db->attribute(AttributeName	, [$newvalue])
	Function: get/set DBI::db handle attribute
	Returns	: current state	of the attribute
	Args	: name of the attribute	and optional new setting of attribute
	Status	: public

	 Under Bio::DB::GFF::Adaptor::dbi::caching_handle the DBI::db
	 attributes that are usually set using hashref calls are unavailable.
	 Use attribute() instead.  For example,	instead	of:

	   $dbh->{AutoCommit} =	0;

	 use

	   $dbh->attribute(AutoCommit=>0);

BUGS
       Report to the author.

SEE ALSO
       DBI, Bio::DB::GFF, bioperl

AUTHOR
       Lincoln Stein <lstein@cshl.org>.

       Copyright (c) 2001 Cold Spring Harbor Laboratory.

       This library is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

perl v5.24.1			 Bio::DB::GFF::Adaptor::dbi::caching_handle(3)

NAME | SYNOPSIS | DESCRIPTION | USAGE | BUGS | SEE ALSO | AUTHOR

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