November 2014 - developers-list

Win32 build question
by g4＠novadsp.com 29 Nov '14

29 Nov '14

Hello and thanks for MonetDB. Splendid stuff. Brilliant. I am trying to build a 32 bit version of 11.19.3 on Windows from the latest tarball. Root folder is R:\src\libraries\MonetDB-11.19.3. Building in R:\src\libraries\MonetDB-11.19.3\bin The build is failing at the point shown below. What have I missed here? The build folder is a sibling of /NT as indicated in the windowsbuild.rst ...? Many thanks for any pointers. Jerry. -------------------------snip-------------------------- copy ".\..\..\..\monetdb5\scheduler\run_isolate.mal" "run_isolate.mal" 1 file(s) copied. if not exist "tools" mkdir "tools" copy ".\..\..\monetdb5\tools\Makefile.msc" "tools\Makefile" 1 file(s) copied. cd "tools" && U:\vs2013\VC\BIN\nmake.exe /nologo DEBUG=1 "prefix=R:\src\ libraries\MonetDB-11.19.3\bin" "bits=32" all NMAKE : fatal error U1073: don't know how to make '..\..\gdk\libbat.lib' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop. NMAKE : fatal error U1077: 'cd' : return code '0x2' Stop. NMAKE : fatal error U1077: 'U:\vs2013\VC\BIN\nmake.exe' : return code '0x2' Stop. R:\src\libraries\MonetDB-11.19.3\bin> -------------------------snip-------------------------- Platform details: Windows 7x64 using VS2013 pro x86 command shell. I've got a very simple script which sets up the correct include/lib paths and then invokes nmake thus: SET LIBOPENSSL=U:\pkg\OpenSSL\Win32 SET LIBICONV=U:\pkg\monet\iconv-1.9.2.win32 SET LIBZLIB=U:\pkg\monet\zlib-1.2.5 SET LIBXML2=U:\pkg\monet\libxml2-2.7.8.win32 SET LIBPCRE=U:\pkg\monet\pcre-7.0-bin SET INCLUDE=%INCLUDE%;U:\pkg\monet\iconv-1.9.2.win32\include;U:\pkg\monet\pcre-7 .0-bin\include nmake /D -f ..\NT\makefile DEBUG=1 HAVE_OPENSSL=1 HAVE_SQL=1 HAVE_MONETDB5=1 all

1 0

Re: MonetDB: default - use column_id instead of schema,table,column ...
by Niels Nes 29 Nov '14

29 Nov '14

On Sat, Nov 29, 2014 at 10:37:24AM +0100, Niels Nes wrote: > Changeset: f49a132fc195 for MonetDB > URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=f49a132fc195 > Modified Files: > sql/backends/monet5/sql_statistics.c > sql/scripts/80_statistics.sql > sql/storage/store.c > Branch: default > Log Message: > > use column_id instead of schema,table,column names to speed up insert and > lookup's beware the schema for the statistics table changed. Do a drop table statistics and recreate using the create statement in the 80_statistics.sql script. Niels > > > diffs (69 lines): > > diff --git a/sql/backends/monet5/sql_statistics.c b/sql/backends/monet5/sql_statistics.c > --- a/sql/backends/monet5/sql_statistics.c > +++ b/sql/backends/monet5/sql_statistics.c > @@ -103,7 +103,7 @@ sql_analyze(Client cntxt, MalBlkPtr mb, > > if (col && strcmp(bc->name, col)) > continue; > - snprintf(dquery, 8192, "delete from sys.statistics where \"schema\" ='%s' and \"table\"='%s' and \"column\"='%s';", b->name, bt->name, bc->name); > + snprintf(dquery, 8192, "delete from sys.statistics where \"column_id\" = %d;", c->base.id); > if (samplesize > 0) { > bsample = BATsample(bn, (BUN) 25000); > } else > @@ -147,8 +147,7 @@ sql_analyze(Client cntxt, MalBlkPtr mb, > snprintf(maxval, 4, "nil"); > snprintf(minval, 4, "nil"); > } > - snprintf(query, 8192, "insert into sys.statistics values('%s','%s','%s','%s',%d,now()," LLFMT "," LLFMT "," LLFMT "," LLFMT ",'%s','%s',%s);", b->name, bt->name, bc->name, c->type.type->sqlname, width, > - (samplesize ? samplesize : sz), sz, uniq, nils, minval, maxval, sorted ? "true" : "false"); > + snprintf(query, 8192, "insert into sys.statistics values(%d,'%s',%d,now()," LLFMT "," LLFMT "," LLFMT "," LLFMT ",'%s','%s',%s);", c->base.id, c->type.type->sqlname, width, (samplesize ? samplesize : sz), sz, uniq, nils, minval, maxval, sorted ? "true" : "false"); > #ifdef DEBUG_SQL_STATISTICS > mnstr_printf(cntxt->fdout, "%s\n", dquery); > mnstr_printf(cntxt->fdout, "%s\n", query); > diff --git a/sql/scripts/80_statistics.sql b/sql/scripts/80_statistics.sql > --- a/sql/scripts/80_statistics.sql > +++ b/sql/scripts/80_statistics.sql > @@ -21,9 +21,7 @@ > > > CREATE TABLE sys.statistics( > - "schema" string, > - "table" string, > - "column" string, > + "column_id" integer, > "type" string, > width integer, > stamp timestamp, > diff --git a/sql/storage/store.c b/sql/storage/store.c > --- a/sql/storage/store.c > +++ b/sql/storage/store.c > @@ -4317,12 +4317,8 @@ sql_trans_dist_count( sql_trans *tr, sql > sql_schema *sys = find_sql_schema(tr, "sys"); > sql_table *stats = find_sql_table(sys, "statistics"); > if (stats) { > - sql_column *stats_schema = find_sql_column(stats, "schema"); > - sql_column *stats_table = find_sql_column(stats, "table"); > - sql_column *stats_column = find_sql_column(stats, "column"); > - oid rid = table_funcs.column_find_row(tr, stats_column, col->base.name, NULL, > - stats_table, col->t->base.name, NULL, > - stats_schema, col->t->s->base.name, NULL, NULL); > + sql_column *stats_column_id = find_sql_column(stats, "column_id"); > + oid rid = table_funcs.column_find_row(tr, stats_column_id, &col->base.id, NULL); > if (rid != oid_nil) { > sql_column *stats_unique = find_sql_column(stats, "unique"); > void *v = table_funcs.column_find_value(tr, stats_unique, rid); > @@ -4344,12 +4340,8 @@ sql_trans_ranges( sql_trans *tr, sql_col > sql_schema *sys = find_sql_schema(tr, "sys"); > sql_table *stats = find_sql_table(sys, "statistics"); > if (stats) { > - sql_column *stats_schema = find_sql_column(stats, "schema"); > - sql_column *stats_table = find_sql_column(stats, "table"); > - sql_column *stats_column = find_sql_column(stats, "column"); > - oid rid = table_funcs.column_find_row(tr, stats_column, col->base.name, NULL, > - stats_table, col->t->base.name, NULL, > - stats_schema, col->t->s->base.name, NULL, NULL); > + sql_column *stats_column_id = find_sql_column(stats, "column_id"); > + oid rid = table_funcs.column_find_row(tr, stats_column_id, &col->base.id, NULL); > if (rid != oid_nil) { > sql_column *stats_min = find_sql_column(stats, "minval"); > sql_column *stats_max = find_sql_column(stats, "maxval"); > _______________________________________________ > checkin-list mailing list > checkin-list(a)monetdb.org > https://www.monetdb.org/mailman/listinfo/checkin-list -- Niels Nes, Centrum Wiskunde & Informatica (CWI) Science Park 123, 1098 XG Amsterdam, The Netherlands room L3.14, phone ++31 20 592-4098 sip:4098@sip.cwi.nl url: http://www.cwi.nl/~niels e-mail: Niels.Nes(a)cwi.nl

1 0

Announcement: New Oct2014-SP1 Bugfix release of MonetDB suite
by Sjoerd Mullender 27 Nov '14

27 Nov '14

The MonetDB team at CWI/MonetDB BV is pleased to announce the Oct2014-SP1 bugfix release of the MonetDB suite of programs. More information about MonetDB can be found on our website at <http://www.monetdb.org/>. For details on this release, please see the release notes at <http://www.monetdb.org/Downloads/ReleaseNotes>. As usual, the download location is <http://dev.monetdb.org/downloads/>. Oct 2014-SP1 bugfix release MonetDB5 Server * Fixed adding of 0 intervals to dates. Build Environment * The libraries included in the Windows installers have been upgraded. We now use libxml2-2.9.2, openssl-1.0.1j, pcre-8.36, and zlib-1.2.8. MonetDB Common * Implemented a change to the way in which string bats are appended. We now try harder to limit the growth of the string heap. * Fixed some problems with BATsample. It was possible for BATsample to return a value that was just beyond the end of the sampled BAT. Also, on some systems the range of the rand() function is rather limited (0..32767) and trying to get a sample larger than this range would result in an infinite loop. SQL * Fixed sys.queue() implementation to report on other queries being executed. * A number of bugs were fixed in the code to upgrade a database from previous releases. This version should fix the upgrade of a database that had been upgraded to the Oct2014 release, but also properly upgrade directly from Jan2014 and Feb2013 releases. Bug Fixes * 3580: cosmetic change (append newline) * 3609: Incorrect use of generate_series * 3611: quantile() and median() commands crash when used 2x on the same variable on a null table * 3612: assertion failure when deleting rows from table to which a FK constraint is defined * 3620: ORDER BY broken when using UNION ALL * 3621: Hexadecimal literal vs decimal literal

1 0

Database can't started.
by Mhd Sulhan 24 Nov '14

24 Nov '14

I have tried to run monetdb version 11.19.3 and monetdb-e46b810ccbd0 and both can't start database. My machine is Linux x86, Linux bubu 3.17.3-1-ARCH #1 SMP PREEMPT Fri Nov 14 22:56:01 CET 2014 i686 GNU/Linux with glibc 2.20. I compile monetdb with this options, ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --disable-assert \ --without-rubygem --disable-testing --enable-optimize --enable-rintegration I can run monetdbd, but fail when running monetdb start <db> or mclient -u <user> -d <db>. Here is some log when I'm running monetdb start, $ mclient -u monetdb -d cdr password: monetdbd: internal error while starting mserver, please refer to the logs With this email, I also attach merovingian.log. -- Salam hormat, Mhd Sulhan { phone: 08567826625, gtalk: m.shulhan, github: shuLhan }

2 2

Re: Resource on the PHP API for monetdb
by Pierre-Adrien Coustillas 24 Nov '14

24 Nov '14

Hi, There is a package pour php5 monetdb. For debian : https://www.monetdb.org/downloads/deb/dists/wheezy/monetdb/binary-amd64/ package : php5-monetdb-client_11.19.3-20141028_all.deb There is two file : php_mapi.inc and php_monetdb.php Pierre -- 1G6 52 route de bischwiller 67300 Schiltigheim Société de Services et de Formations en Logiciels Libres http://1g6.biz Tél : 06 64 63 70 35 ----- Mail original ----- De: "Leon-Constantin Fopa" <leon-constantin.fopa(a)imag.fr> À: "Communication monetdb" <users-list(a)monetdb.org> Cc: "developers monetdb" <developers-list(a)monetdb.org> Envoyé: Lundi 24 Novembre 2014 09:04:51 Objet: Resource on the PHP API for monetdb Hi every one, I'm interested in accessing monetdb from a PHP script. Can someone provide me a link on resource with introduce that. The research of the keyword "monetdb" from the the http://php.net website search engine give no related result. thanks in advance, Best regards, Fopa Léon Constantin _______________________________________________ users-list mailing list users-list(a)monetdb.org https://www.monetdb.org/mailman/listinfo/users-list

1 0

Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release
by Ashish Kumar Singh 21 Nov '14

21 Nov '14

Hi, Below are the steps. Unzip archive in to /opt/monetdb_test/ directroy to minimise changes in the script datbase can live anywhere in the file system. Single Big File Import: 1. First create a database using Monetdb October2014 build called pbsworks 2. Create data base schema using schema provided in file schema.sql. Cat all files present inside testdata directory in to on single file by using following command: cat * > ../merged_data Load this merged file in to database using script single_import.sql from mclient Note down the timing, usually 3-5 minutes on 4 core 17 GB machine on amazon. Multiple small File Import: 1. First create a database using Monetdb October2014 build called pbsworks 2. Create data base schema using schema provided in file schema.sql. 3. Load files in to database using multiple_import.sql using mclient Regards, Ashish From: Anthony Damico <ajdamico(a)gmail.com<mailto:ajdamico@gmail.com>> Reply-To: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Date: Monday, 17 November 2014 3:51 pm To: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Cc: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Subject: Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release please provide a list of every command that you executed to reproduce the problem. you need to make the list of commands as short as possible, so people trying to help you are not wasting time on irrelevant code.. thanks!! On Mon, Nov 17, 2014 at 4:22 AM, Ashish Kumar Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> wrote: Thanks for looking in to it, I have uploaded required test files to you at below link: https://ftin.india.altair.com:8443/message/eJCZlisrascBO00ffEVsQu<https://ftin.india.altair.com:8443/message/eJCZlisrascBO00ffEVsQu> Regards, Ashish From: Anthony Damico <ajdamico(a)gmail.com<mailto:ajdamico@gmail.com>> Reply-To: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Date: Saturday, 15 November 2014 2:40 pm To: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Cc: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Subject: Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release could you provide a minimal reproducible example? the less code that re-creates the problem, the better. thanks http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducib… On Sat, Nov 15, 2014 at 1:45 AM, Ashish Kumar Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> wrote: Additional information here, If I merge all these files in to one file and then import to monetdb then time taken is 3-5 minutes as compared to 10-15 hours with October 2014 branch. Hopefully some one from moentdb team will look in to this. I am glad to see that inspite of this slowness ( due to which this build is unusable) the segfaults are gone! Regards, Ashish From: Ashish Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> Date: Friday, 14 November 2014 7:41 pm To: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Cc: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Subject: Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release Is any body else seeing this problem with October,2014 release? I wish developer team can provide some insights in this area. Regards, Ashish From: Ashish Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> Date: Thursday, 13 November 2014 11:22 pm To: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Cc: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Subject: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release All, With October,2014 release we are stucked in to very strange performance issue while importing data on virtualised environments. On Virtual machines in our local VMware servers and amazon machine we are seeing import performance has downgraded to close to 15 to 20 while importing ~ 2000 files as compared to 1 hour time being taken with old release. This we are seeing consistently with CentOS, SLES vm and configuration is 4 Core 33 GB machine. We tried on quite a few amazon vm just to make sure its not an issue with a particular instance setup. On a physical machine of 4 core 24 GB we are able to match speed of import with old monetdb. We are issuing copy into command through JDBC connection. Can you guys help me with pointers on this issue, I will be happy to share any debug info. Regards, Ashish Kumar Singh Mobile: +91-9972045095<tel:%2B91-9972045095> Skype: toashishk(a)gmail.com<mailto:toashishk@gmail.com> _______________________________________________ users-list mailing list users-list(a)monetdb.org<mailto:users-list@monetdb.org> https://www.monetdb.org/mailman/listinfo/users-list _______________________________________________ users-list mailing list users-list(a)monetdb.org<mailto:users-list@monetdb.org> https://www.monetdb.org/mailman/listinfo/users-list

2 4

python-monetdb
by Gijs Molenaar 17 Nov '14

17 Nov '14

Hi MonetDB developers, I noticed the python3 package was broken, and pypi was outdated. I lost the key for committing to the tree, so I did the following: * I created a temporary fork on github: https://github.com/gijzelaerr/python-monetdb * I've merge the python2 and python3 code using six. This is a reverse of the split I previously did, since it is just much easier to manage one single code base. People make mistakes. Also this way the package on pypi works with all pythons at the same time (most important reason). * cleanup the test suite * i'm using tox myself now for running the test suite with all the various pythons * I've uploaded a new version to pypi, with version ID 11.19.3.1 * This version is tested with python 2.6, 2.7 3.3, 3.4 and pypy I propose you just take my changes and merge them back in your tree, then I remove the fork. Also probably it is wise you incorporate the upload to pypi in your release process. Most people probably use pypi for installing their python requirements. For this you need to create a pypi account and let me know the username so I can give this account authorisation to upload the package. You can upload to pypi from the source folder using: $ python setup.py sdist upload Sorry for any inconvenience but I just needed to get python3 support quickly. -- Gijs Molenaar http://pythonic.nl <http://gijs.pythonic.nl>

1 0

Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release
by Ashish Kumar Singh 17 Nov '14

17 Nov '14

Thanks for looking in to it, I have uploaded required test files to you at below link: https://ftin.india.altair.com:8443/message/eJCZlisrascBO00ffEVsQu<https://ftin.india.altair.com:8443/message/eJCZlisrascBO00ffEVsQu> Regards, Ashish From: Anthony Damico <ajdamico(a)gmail.com<mailto:ajdamico@gmail.com>> Reply-To: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Date: Saturday, 15 November 2014 2:40 pm To: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Cc: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Subject: Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release could you provide a minimal reproducible example? the less code that re-creates the problem, the better. thanks http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducib… On Sat, Nov 15, 2014 at 1:45 AM, Ashish Kumar Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> wrote: Additional information here, If I merge all these files in to one file and then import to monetdb then time taken is 3-5 minutes as compared to 10-15 hours with October 2014 branch. Hopefully some one from moentdb team will look in to this. I am glad to see that inspite of this slowness ( due to which this build is unusable) the segfaults are gone! Regards, Ashish From: Ashish Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> Date: Friday, 14 November 2014 7:41 pm To: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Cc: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Subject: Re: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release Is any body else seeing this problem with October,2014 release? I wish developer team can provide some insights in this area. Regards, Ashish From: Ashish Singh <ashishkumar.singh(a)altair.com<mailto:ashishkumar.singh@altair.com>> Date: Thursday, 13 November 2014 11:22 pm To: "developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>" <developers-list(a)monetdb.org<mailto:developers-list@monetdb.org>> Cc: "users-list(a)monetdb.org<mailto:users-list@monetdb.org>" <users-list(a)monetdb.org<mailto:users-list@monetdb.org>> Subject: Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release All, With October,2014 release we are stucked in to very strange performance issue while importing data on virtualised environments. On Virtual machines in our local VMware servers and amazon machine we are seeing import performance has downgraded to close to 15 to 20 while importing ~ 2000 files as compared to 1 hour time being taken with old release. This we are seeing consistently with CentOS, SLES vm and configuration is 4 Core 33 GB machine. We tried on quite a few amazon vm just to make sure its not an issue with a particular instance setup. On a physical machine of 4 core 24 GB we are able to match speed of import with old monetdb. We are issuing copy into command through JDBC connection. Can you guys help me with pointers on this issue, I will be happy to share any debug info. Regards, Ashish Kumar Singh Mobile: +91-9972045095<tel:%2B91-9972045095> Skype: toashishk(a)gmail.com<mailto:toashishk@gmail.com> _______________________________________________ users-list mailing list users-list(a)monetdb.org<mailto:users-list@monetdb.org> https://www.monetdb.org/mailman/listinfo/users-list

1 0

Big Slowdown (15-20X ) on import functions in Monetdb October 2014 Release
by Ashish Kumar Singh 15 Nov '14

15 Nov '14

All, With October,2014 release we are stucked in to very strange performance issue while importing data on virtualised environments. On Virtual machines in our local VMware servers and amazon machine we are seeing import performance has downgraded to close to 15 to 20 while importing ~ 2000 files as compared to 1 hour time being taken with old release. This we are seeing consistently with CentOS, SLES vm and configuration is 4 Core 33 GB machine. We tried on quite a few amazon vm just to make sure its not an issue with a particular instance setup. On a physical machine of 4 core 24 GB we are able to match speed of import with old monetdb. We are issuing copy into command through JDBC connection. Can you guys help me with pointers on this issue, I will be happy to share any debug info. Regards, Ashish Kumar Singh Mobile: +91-9972045095 Skype: toashishk(a)gmail.com

1 2

Timestamp accuracy: milli-seconds or micro-seconds
by Stefan Manegold 07 Nov '14

07 Nov '14

Hi, with the Oct2014 release of MonetDB (I did no (yet) check any other version), I just came across the following: It appears that while timestamps are rendered with 6 decimal digits, i.e., suggesting micro-seconds accuracy/resolution, only milli-seconds are considered: sql>select cast('1312-11-10 12:11:10.123456' as timestamp) , cast('1312-11-10 12:11:10' as timestamp) + 0.123456 , cast('1312-11-10 12:11:10' as timestamp) + interval '0.123456' second; +----------------------------+----------------------------+----------------------------+ | L1 | L2 | sql_add_single_value | +============================+============================+============================+ | 1312-11-10 12:11:10.123000 | 1312-11-10 12:11:10.123000 | 1312-11-10 12:11:10.123000 | +----------------------------+----------------------------+----------------------------+ 1 tuple (5.459ms) Is this a bug or a "feature"? Thanks! Stefan -- | Stefan.Manegold(a)CWI.nl | DB Architectures (DA) | | www.CWI.nl/~manegold/ | Science Park 123 (L321) | | +31 (0)20 592-4212 | 1098 XG Amsterdam (NL) |

2 1