Re: Memory leak, DBI 1.55 + DBD::ODBC 1.13 + MS SQL 2000

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----- Original Message -----
From: "Fi Dot"
To:
Cc: ; ; ;

Sent: Monday, May 21, 2007 4:42 PM
Subject: Memory leak, DBI 1.55 + DBD::ODBC 1.13 + MS SQL 2000


> Hi All!
>
> Recently I have bumped into a memory leak happening in DBI.
>
> Running DBI version 1.55, DBD::ODBC version 1.13 on Windows XP SP2,
> Active State Active Perl 5.8 build 819. More comprehensive build info
> at the bottom of this email.
>
> You could find the code I am executing attached to this message.
>
> I was executing queries returning multiple record-sets with fields of
> text type in them and.. well, the memory usage of my script just grows
> drastically. Digging into this, I have found that it looks like
> DBD::ODBC is not freeing up memory buffers allocated for storing the
> current record when switching to the next record-set.
>
> Here are my findings:
>
> - Look on foo.sql defining my stored procedure. It is returning a
> record set of ints, and then another record set of text fields. This
> code will grow my script's memory footprint a lot every iteration
> through the for {} loop defined on line 22 of foo.pl.
> - If I will swap the select's in stored procedure, making text fields
> go first, memory footprint will still grow, but much slower.
> - This never happens when I have one single record set returned.
> - Undeffing the connection and calling DBI's disconnect() method does not
> help
> - Notice I set LongReadLen value to 16 megabytes (line 18 of foo.pl)?
> This value directly affects the amount of memory used by my script.
> The bigger it is, the larger my mem footprint will be:
>
> 16 Megabytes: 150 megabytes of RAM used
> 8 Megabytes: 80 megabytes of RAM used
> 4 Megabytes: 40 megabytes of RAM used.
>
> - Text fields were taken just as a good example for watching memory
> usage grow rapidly, in general this is happening with any query
> having more than one record-set, just with slower rates.
>
> This looks like a bug in DBD::ODBC... Had anybody on the list seen
> something similar? Are there any known fixes for this?
>
> Thanx!
>
> Fi.
>
> My Perl build config (apl is just an alias in BASH):
>
> $ apl -v
>
> This is perl, v5.8.8 built for MSWin32-x86-multi-thread
> (with 33 registered patches, see perl -V for more detail)
>
> Copyright 1987-2006, Larry Wall
>
> Binary build 819 [267479] provided by ActiveState
> http://www.ActiveState.com
> Built Aug 29 2006 12:42:41
>
> Perl may be copied only under the terms of either the Artistic License or
> the
> GNU General Public License, which may be found in the Perl 5 source kit.
>
> Complete documentation for Perl, including FAQ lists, should be found on
> this system using "man perl" or "perldoc perl". If you have access to the
> Internet, point your browser at http://www.perl.org/, the Perl Home Page.
>
> $ apl -V
> Summary of my perl5 (revision 5 version 8 subversion 8) configuration:
> Platform:
> osname=MSWin32, osvers=5.0, archname=MSWin32-x86-multi-thread
> uname=''
> config_args='undef'
> hint=recommended, useposix=true, d_sigaction=undef
> usethreads=define use5005threads=undef useithreads=define
> usemultiplicity=de
> fine
> useperlio=define d_sfio=undef uselargefiles=define usesocks=undef
> use64bitint=undef use64bitall=undef uselongdouble=undef
> usemymalloc=n, bincompat5005=undef
> Compiler:
> cc='cl', ccflags
> ='-nologo -GF -W3 -MD -Zi -DNDEBUG -O1 -DWIN32 -D_CONSOLE -
> DNO_STRICT -DHAVE_DES_FCRYPT -DNO_HASH_SEED -DUSE_SITECUSTOMIZE -DPERL_IMPLICIT_
> CONTEXT -DPERL_IMPLICIT_SYS -DUSE_PERLIO -DPERL_MSVCRT_READFIX',
> optimize='-MD -Zi -DNDEBUG -O1',
> cppflags='-DWIN32'
> ccversion='12.00.8804', gccversion='', gccosandvers=''
> intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
> d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
> ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='__int64',
> lseeksi
> ze=8
> alignbytes=8, prototype=define
> Linker and Libraries:
> ld='link', ldflags
> '-nologo -nodefaultlib -debug -opt:ref,icf -libpath:"C:
> \Perl\lib\CORE" -machine:x86'
> libpth=\lib
> libs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib
> comdlg32
> .lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib
> uuid.lib ws2_
> 32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib msvcrt.lib
> perllibs= oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib
> comd
> lg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib netapi32.lib
> uuid.lib
> ws2_32.lib mpr.lib winmm.lib version.lib odbc32.lib odbccp32.lib
> msvcrt.lib
> libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl58.lib
> gnulibc_version=''
> Dynamic Linking:
> dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
> cccdlflags=' ',
> lddlflags='-dll -nologo -nodefaultlib -debug -opt:ref,icf -
> libpath:"C:\Perl\lib\CORE" -machine:x86'
>
>
> Characteristics of this binary (from libperl):
> Compile-time options: MULTIPLICITY PERL_IMPLICIT_CONTEXT
> PERL_IMPLICIT_SYS PERL_MALLOC_WRAP
> PL_OP_SLAB_ALLOC USE_ITHREADS USE_LARGE_FILES
> USE_PERLIO USE_SITECUSTOMIZE
> Locally applied patches:
> ActivePerl Build 819 [267479]
> Iin_load_module moved for compatibility with build 806
> PerlEx support in CGI::Carp
> Less verbose ExtUtils::Install and Pod::Find
> Patch for CAN-2005-0448 from Debian with modifications
> Rearrange @INC so that 'site' is searched before 'perl'
> Partly reverted 24733 to preserve binary compatibility
> 28671 Define PERL_NO_DEV_RANDOM on Windows
> 28376 Add error checks after execing PL_cshname or PL_sh_path
> 28305 Pod::Html should not convert "foo" into ``foo''
> 27736 Make perl_fini() run with Sun WorkShop compiler
> 27619 Bug in Term::ReadKey being triggered by a bug in
> Term::ReadLine
> 27549 Move DynaLoader.o into libperl.so
> 27528 win32_pclose() error exit doesn't unlock mutex
> 27527 win32_async_check() can loop indefinitely
> 27515 ignore directories when searching @INC
> 27359 Fix -d:Foo=bar syntax
> 27210 Fix quote typo in c2ph
> 27203 Allow compiling swigged C++ code
> 27200 Make stat() on Windows handle trailing slashes correctly
> 27194 Get perl_fini() running on HP-UX again
> 27133 Initialise lastparen in the regexp structure
> 27034 Avoid "Prototype mismatch" warnings with autouse
> 26970 Make Passive mode the default for Net::FTP
> 26921 Avoid getprotobyname/number calls in IO::Socket::INET
> 26897,26903 Make common IPPROTO_* constants always available
> 26670 Make '-s' on the shebang line parse -foo=bar switches
> 26536 INSTALLSCRIPT versus INSTALLDIRS
> 26379 Fix alarm() for Windows 2003
> 26087 Storable 0.1 compatibility
> 25861 IO::File performace issue
> 25084 long groups entry could cause memory exhaustion
> 24699 ICMP_UNREACHABLE handling in Net::Ping
> Built under MSWin32
> Compiled at Aug 29 2006 12:42:41
> %ENV:
>
> @INC:
> c:/Perl/site/lib
> c:/Perl/lib
> .
>