Re: FW: Db ping function
- From: Jared Still <jkstill@xxxxxxxxx>
- To: mark.bobak@xxxxxxxxxxxxxxx
- Date: Mon, 20 Sep 2004 10:08:30 -0700
>
> FYI: select SYSDATE from DUAL /* ping */ is the method by which the
> DBD::Oracle perl module checks to make sure it has a connection to the
> database. It's not in our code -- it's in the perl DBI/DBD code! There
> has
> to be some way to disable it, because I'm pretty sure it's not
> necessary.
On Mon, 20 Sep 2004 12:31:31 -0400, Bobak, Mark
<mark.bobak@xxxxxxxxxxxxxxx> wrote:
> Ok, Perl experts....any thoughts/comments/suggestions on this one?
> Any way to disable this?
>
The ping method is part of the DBI module, and does nothing.
The driver method is used to over-ride it. Here is ping from DBD::Oracle:
sub ping {
my($dbh) = @_;
my $ok = 0;
eval {
local $SIG{__DIE__};
local $SIG{__WARN__};
# we know that Oracle 7 prepare does a describe so this will
# actually talk to the server and is this a valid and cheap test.
my $sth = $dbh->prepare("select SYSDATE from DUAL /* ping */");
# But Oracle 8+ doesn't talk to server unless we describe the query
$ok = $sth && $sth->FETCH('NUM_OF_FIELDS');
};
return ($@) ? 0 : $ok;
}
Obviously it does a select from dual.
It is not called implicitly by the DBD::Oracle module though, so
it *is* in their code, somewhere.
Jared
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