Re: finishing sth using Childhandles

Here's a little test:

#!/usr/bin/perl
use DBI;
my $dbh = DBI->connect('dbi:Sybase:server=DBA_SQL', '...', '...');
my $sth = $dbh->prepare("select * from histo..table_size where serverName =
'BPSREC5_SQL'");
$sth->execute;
DBI->trace(5);

undef $dbh;

This produces the following:

DBI 1.51-ithread default trace level set to 0x0/5 (pid 22393)
Note: perl is running without the recommended perl -w option
<> DESTROY(DBI::st=HASH(0x9d98514)) ignored for outer handle (inner
DBI::st=HASH(0x9d984fc) has ref cnt 1)
-> DESTROY for DBD::Sybase::st (DBI::st=HASH(0x9d984fc)~INNER)
thr#9bdc008
syb_st_finish() -> ct_cancel(CS_CANCEL_ALL)
clear_sth_flags() -> resetting ACTIVE, moreResults, dyn_execed,
exec_done
clear_sth_flags() -> reset inUse flag
syb_st_destroy: called on 9d9abb8...
syb_st_destroy(): freeing imp_sth->statement
ct_cmd_drop() -> CS_COMMAND 9d9aa28
syb_st_destroy(): cmd dropped: 1
<- DESTROY= undef
dbih_clearcom 0x9d984fc (com 0x9d9abb8, type 3) done.

<> DESTROY(DBI::db=HASH(0x9d95b94)) ignored for outer handle (inner
DBI::db=HASH(0x9d96c18) has ref cnt 1)
-> DESTROY for DBD::Sybase::db (DBI::db=HASH(0x9d96c18)~INNER)
thr#9bdc008
syb_db_disconnect() -> ct_close()
<- DESTROY= undef
dbih_clearcom 0x9d96c18 (com 0x9d97838, type 2) done.

-- DBI::END
-> disconnect_all for DBD::Sybase::dr
(DBI::dr=HASH(0x9ceb734)~0x9d95ba0) thr#9bdc008
<- disconnect_all= 1 at /usr/lib/perl5/site_perl/5.8.6
/i386-linux-thread-multi/DBI.pm line 698 via /home/pepm01a/tmp/child.pl
line 0
! -> DESTROY in DBD::_::common for DBD::Sybase::dr
(DBI::dr=HASH(0x9d95ba0)~INNER) thr#9bdc008
! <- DESTROY= undef during global destruction
dbih_clearcom 0x9ceb734 (com 0x9cd1dd8, type 1) done.

! <> DESTROY for DBI::dr=HASH(0x9ceb734) ignored (inner handle gone)


As you see this calls the DESTROY for the sth (which cancels the query),
and then calls the DESTROY for the dbh (which closes the connection). There
is no special code in DBD::Sybase to handle this case AFAIK.

Michael





Extranet
henri@xxxxxxxxxxxxx - 29/08/2006 13:44

To: dbi-users

cc:


Subject: Re: finishing sth using Childhandles


Thanks, Tim.
One more question to the group:
If I "undef $dbh" when it is active and it has active (or inactive)
child handles, what happens exactly?
Is an actual $dbh->disconnect() made, and are the $sth's finished at
all? Is it DBD dependent?

Thanks in advance,
Henri.

On Aug 28, 2006, at 11:15 PM, Tim Bunce wrote:

On Thu, Aug 24, 2006 at 09:47:56AM +0200, Henri Asseily wrote:
Is the below the correct usage for finishing still active child
handles of a dbh?


foreach my $childh (@{$dbh->{ChildHandles}}) {
$childh->finish() if ($childh->{Type} eq 'st');
}

The children of a dbh will always be sth, but the test is harmless.

I'm getting an error when running the above code:

dbih_setup_fbav: invalid number of fields: -1, NUM_OF_FIELDS
attribute probably not set right

Looks like a bug (in the driver, I'd guess, but you don't say which)
because calling finish should never need to call dbih_setup_fbav.

But checking for Active will probably avoid the problem:

$_->finish for grep { $_->{Active} } @{$dbh->{ChildHandles}};

Tim.




This message and any attachments (the "message") is
intended solely for the addressees and is confidential.
If you receive this message in error, please delete it and
immediately notify the sender. Any use not in accord with
its purpose, any dissemination or disclosure, either whole
or partial, is prohibited except formal approval. The internet
can not guarantee the integrity of this message.
BNP PARIBAS (and its subsidiaries) shall (will) not
therefore be liable for the message if modified.

---------------------------------------------

Ce message et toutes les pieces jointes (ci-apres le
"message") sont etablis a l'intention exclusive de ses
destinataires et sont confidentiels. Si vous recevez ce
message par erreur, merci de le detruire et d'en avertir
immediatement l'expediteur. Toute utilisation de ce
message non conforme a sa destination, toute diffusion
ou toute publication, totale ou partielle, est interdite, sauf
autorisation expresse. L'internet ne permettant pas
d'assurer l'integrite de ce message, BNP PARIBAS (et ses
filiales) decline(nt) toute responsabilite au titre de ce
message, dans l'hypothese ou il aurait ete modifie.

.

Relevant Pages

  • insertion problem...
    ... DBI::db=HASH) undef ... <- DESTROY= undef during global destruction ... Initialising SQL Real Time Logging Jun 3 16:28:03 hostname ...
    (perl.dbi.users)
  • RE: insertion problem...
    ... DBI::db=HASH) undef ... <- DESTROY= undef during global destruction ... Initialising SQL Real Time Logging Jun 3 16:28:03 hostname ...
    (perl.dbi.users)
  • RE: Strange problems with fetchall_arrayref DBI, DBD::mysql
    ... turned tracing off - and the problems started again. ... <- DESTROY= undef at addescuela.cgi line 135 ... This was my current config of DBI and related ...
    (perl.dbi.users)
  • RE: Value deletion
    ... fetch num_fields=1 ... <- DESTROY= undef during global destruction ...
    (perl.dbi.users)
  • Re: forking problem with dbd::mysql
    ... But still has a question for me.We may see this similiar destroy method on DBI class, ... Ok where in child when going out of scope the $dbh should get disconnected. ...
    (perl.beginners)