January 2010 - users-list

[MonetDB-users] Ebuilds for MonetDB
by W-Mark Kubacki 07 Jan '10

07 Jan '10

Hello. I'd like to thank you for MonetDB by providing fresh ebuilds for the suite. And yes, I did find Fabian Groffen's, but they were outdated and removed from main tree. So, find new ones in my Gentoo overlay [1] along with binaries for amd64 and arm on my binhosts [2,3]. Unfortunately Monet features a lot unused configure flags and deviates from the Filesystem Hierarchy Standard (FHS) 2.3 [4] (*), therefore I had to put an extra efford to sieve the first out and have files installed corretly. If you happen to find something I missed, don't hesitate to drop me a line or two. -- Beste Grüße W-Mark Kubacki http://mark.ossdl.de/ [1] http://git.ossdl.de/?p=ossdl-overlay.git;a=summary [2] http://binhost.ossdl.de/x86_64-pc-linux-gnu/ , http://binhost.ossdl.de/x86_64-pc-linux-gnu/Packages [3] http://binhost.ossdl.de/armv5tel-softfloat-linux-gnueabi/ , http://binhost.ossdl.de/armv5tel-softfloat-linux-gnueabi/Packages [4] http://www.pathname.com/fhs/

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[MonetDB-users] vaultkey, embedded, and merovingian.
by Guillaume Yziquel 05 Jan '10

05 Jan '10

Hi. I've been creating a database from a call to monetdb_sql() from libembeddedsql5.so, from my OCaml binding. After that, I start up a merovingian process and I do the following: > yziquel@seldon:~/git/ocaml-monetdb5$ monetdb status > name state uptime health last crash > testdb stopped 100%, 49s - > yziquel@seldon:~/git/ocaml-monetdb5$ monetdb start testdb > starting database 'testdb'... FAILED > start: starting 'testdb' failed: cannot start database 'testdb': no .vaultkey found (did you create the database with `monetdb create testdb`?) I'm quite baffled by the error I just got. What is this .vaultkey problem? All the best, -- Guillaume Yziquel http://yziquel.homelinux.org/

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[MonetDB-users] Inserting '\' into varchar(1)
by Alex Bo. 04 Jan '10

04 Jan '10

Hi, I think I found a bug: I can't seem to insert the character '\' into Monet with COPY INTO when I use a single character column: 1. I have a text file that only contains this: '1,"\\"' 2. create table test1 (f1 int, f2 varchar(1)) 3. copy into test1 from 'C:\test1.txt' using delimiters ',','\r\n','"' null as ''; I get: SQLException:sql:value '\\' from line 1 field 2 not inserted, expecting type str If I change the field size from varchar(1) to varchar(2) it works. (Aug09 & Nov09 on Windows) Is this a bug? Thanks & happy new year. -- View this message in context: http://old.nabble.com/Inserting-%27%5C%27-into-varchar%281%29-tp27010393p27… Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Nightly builds are still OK?
by Guillaume Yziquel 04 Jan '10

04 Jan '10

Hi. I've been trying to fetch nightly builds, but on the webpage http://monetdb.cwi.nl/testing/projects/monetdb/Current/.DailyBuilds./ it seems that the last nightly build was one week or so ago. Are nightly builds still working fine? Just to know... All the best, -- Guillaume Yziquel http://yziquel.homelinux.org/

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[MonetDB-users] Error on "rank() over (order by sum(.."
by Makoto YUI 04 Jan '10

04 Jan '10

Hi, The following query yields "SELECT: subquery result missing" error on Nov2009-SP1. select s_name, sum(score), rank() over (order by sum(score) desc) from score_table group by s_name -- preparation create table score_table ( s_name varchar(20), subject varchar(10), score int ); insert into score_table values('foo','english',70); insert into score_table values('foo','history',50); insert into score_table values('foo','math',60); insert into score_table values('bar','english',45); insert into score_table values('bar','history',75); It seems allowed to use aggregation functions in "over(..)" in other databases. http://www.google.com/search?q="rank()+over+(order+by+sum(" Thanks, Makoto

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[MonetDB-users] Limitation in "create table .. as subquery"
by Makoto YUI 04 Jan '10

04 Jan '10

Hello, create table t1 (f1 int); insert into t1 values (1); insert into t1 values (2); create table t2 as (select * from t1 limit 1) with data; The above "create table" caused the following syntax error on the Limit clause. syntax error, unexpected LIMIT, expecting INTERSECT or EXCEPT or UNION or ')' in: "create table t2 as (select * from t1 limit" Is this an expected behavior? This "subquery" issue might be related. http://sourceforge.net/tracker/?func=detail&atid=482468&aid=2620437&group_i… I'm using Nov2009-SP1 on Linux. Thanks, Makoto

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[MonetDB-users] Problem with BSS initialisation.
by Guillaume Yziquel 04 Jan '10

04 Jan '10

Hello. I've spent quite some time lately debugging my issue with OCaml binding of MonetDB libraries: http://www.mail-archive.com/caml-list@yquem.inria.fr/msg05449.html It seems that the BSS is not properly initialised to 0 when dynamically loaded. It seems that the code in mal_box.c relies on the fact that BSS is initialised to 0 when loaded. I'm still trying to figure out how exactly is the libmonetdb5.so library loaded. This is still an obscure point. ltrace did not provide useful information. Advice welcome. -- Guillaume Yziquel http://yziquel.homelinux.org/

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[MonetDB-users] Multiple core usage on Windows
by Alex Bo. 03 Jan '10

03 Jan '10

Hi, Does MonetDB split a single query plan over multiple CPU cores when its possible? (maybe the DataFlow optimizer?) For example, the following query could be executed by all cores in parallel: SELECT field1,SUM(field2) FROM Table1 GROUP BY field1 When i tried to see if it does, i got some weird results: (I am running MonetDB on Windows, on a quad core machine) When I set '--set gdk_nr_threads=1', queries never seem to use more than 25%. (seems logical since only one CPU core is being deployed) When I set '--set gdk_nr_threads=2', queries use up to 50% CPU, but the query is ~15% slower. When I set '--set gdk_nr_threads=4', queries use up to 98% CPU, but the query is take twice as long as with 1 thread. So, my initial assumption that more CPU utilization (more cores over the same query) will result faster query results (where applicable) is wrong. Can it be something specific to the windows platform? or maybe single query execution over multiple cores doesn't work without a specific optimizer flag enabled?... or maybe is it just a bug... Thanks. -- View this message in context: http://old.nabble.com/Multiple-core-usage-on-Windows-tp27002955p27002955.ht… Sent from the monetdb-users mailing list archive at Nabble.com.

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Re: [MonetDB-users] segfault with monetdb_sql().
by Guillaume Yziquel 02 Jan '10

02 Jan '10

Martin Kersten a écrit : >>> >>> Program received signal SIGSEGV, Segmentation fault. >>> [Switching to Thread 0x2aaaaf66d910 (LWP 4061)] >>> 0x00002aaaac676de3 in findBox () from /usr/lib/libmonetdb5.so.5 > > i miss here the line number, seems that is ubunti specific > you can do > print i > print box[i] > print name Providing debian packages of libraries with debugging symbols would be great. > i suspect box[i] is not properly initialized to 0 I'll try to check that. >>> (gdb) backtrace >>> #0 0x00002aaaac676de3 in findBox () from /usr/lib/libmonetdb5.so.5 > this gives one hint, it is likely passed without name causing idcmp to fail >>> #1 0x00002aaaac677086 in openBox () from /usr/lib/libmonetdb5.so.5 >>> #2 0x00002aaab7a51cbb in MTIMEprelude () from > > happens while loading the data/time module. It initializes the "time" > module Should I assume that the mtime.mal + lib_mtime.so is the first one to be loaded? Just to know if some dynamic linking successfully happened before or not. >>> /usr/lib/MonetDB5/lib/lib_mtime.so >>> #3 0x00002aaaac6826cf in ?? () from /usr/lib/libmonetdb5.so.5 >>> #4 0x00002aaaac68b2a0 in runMAL () from /usr/lib/libmonetdb5.so.5 >>> #5 0x00002aaaac67cac7 in MALengine () from /usr/lib/libmonetdb5.so.5 >>> #6 0x00002aaaac67d5f6 in malBootstrap () from /usr/lib/libmonetdb5.so.5 >>> #7 0x00002aaaac669f75 in mal_init () from /usr/lib/libmonetdb5.so.5 >>> #8 0x00002aaaab91ef60 in ?? () from /usr/lib/libembeddedsql5.so >>> #9 0x00002aaaab39b73a in start_thread () from /lib/libpthread.so.0 >>> #10 0x00002aaaab67c69d in clone () from /lib/libc.so.6 >>> #11 0x0000000000000000 in ?? () >>> (gdb) >> >> Please tell me what else could be useful. > > This was already useful, because i added two additional defense lines > to capture improperly set environments. OK. I'll check. >>> I am not an CAML expert, but i guess there may be potential issues >>> in location and dynamic loading of the necessary libraries. >>> Where does CAML get the libraries from? >> >> As a rather general statement, dynamic loading is supported within >> OCaml world. I'm not so sure how this works when it is C code that >> triggers dynamic loading, with OCaml in bytecode mode... > > I have added some extra code to make failing loads more visible. > In general, it seems that the modules are not found at the location I'll ask on the OCaml list for that. >> I would like to pinpoint the segfault more precisely in order to go >> back to the OCaml mailing list about potential dynamic loading issues. > I think it can not find your libraries > > set the variable gdk_debug=10 this will show you the environment > settings as seen upon start. Including the location where it expect > database and libraries to recide. Will do that. However, I believe it is not a problem of location, as this works out fine when the OCaml binding is compiled to native code. All the best, -- Guillaume Yziquel http://yziquel.homelinux.org/

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