- users-list - monetdb.org

[MonetDB-users] sql date
by dariuszs 02 Feb '10

02 Feb '10

Hi, Is there any documentation on how to manipulate dates (add/subtract months, days, years)? Running query: sql>select date '1900-01-01' + interval '100' year; Produces error: Incorrect interval (3>1)..... Thanks. Dariusz.

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[MonetDB-users] size_t vs. var_t on Windows
by Alex Bo. 31 Jan '10

31 Jan '10

Hi, I've been trying to build the MonetDB5 module from the Feb2010 branch from CVS on Windows. However, I am getting this: .\..\..\..\..\src\modules\kernel\group.mx(1330) : warning C4267: '=' : conversion from 'size_t' to 'var_t', possible loss of data .\..\..\..\..\src\modules\kernel\group.mx(1330) : warning C4267: '=' : conversion from 'size_t' to 'var_t', possible loss of data This did not happen in the November releases on Windows. Any ideas on how to approach this? Do I need to use some special flags? Thanks. -- View this message in context: http://old.nabble.com/size_t-vs.-var_t-on-Windows-tp27396298p27396298.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] MonetDB/XQuery stability problems w/ shredding
by Xander Schrijen 29 Jan '10

29 Jan '10

Hi list, I'm using MonetDB/XQuery to run queries on sets of XML documents of all kinds (build files, process descriptions). These sets can range from a few dozen to a few thousand documents, so the speed of MonetDB can be a real boon. However, when shredding these documents there may be a few errors. Sometimes a namespace URI is reported as not well formed, sometimes shredding 'hangs' (esp. when using the batch-import method from the manual), sometimes I can't find a reason. After such an error, the database seems to be corrupted. Sometimes queries for which collections are in the database give errors, sometimes an XPath query doesn't finish. In most cases, the ERROR=.... from mclient doesn't give a proper error (ascii garbage). I reallize these reports are vague. However, even though this happens a lot, reproducing the exact sequence can be hard. (Importing a few 100 documents, waiting for the import error to occur, using the right query to trigger the error...) But as it is now, I don't even know if these things are known, have work-arounds, or require fixing the xml documents upfront. Are there people on the list with experience with this that are willing to help me out? Regards, Xander.

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[MonetDB-users] Announcement: New Nov2009-SP2 bugfix release of MonetDB suite
by Sjoerd Mullender 28 Jan '10

28 Jan '10

The MonetDB team at CWI/MonetDB BV is pleased to announce the Nov2009-SP2 bug fix release of the MonetDB suite of programs. More information on this release will be available at <http://monetdb.cwi.nl/Development/Releases/Nov2009/>. Fixes include: - No need to require bash for running the *-config scripts. (SF bug #2914563) - MonetDB5 development package now contains all development include files. (SF RFE #2929558) - Added support for compiling on OpenBSD (contributed, i.e. not tested by us). - General code improvements, partly inspired by running Coverity Scan. - mclient -D will exit with a non-zero exit code if dumping failed. (SF bug #2925674) - The Python interface now uses the same socket options as the C version, giving a boost in performance. (SF bug #2925750) - Fixed a bug in the Python interface to deal with fields with embedded newline characters. (SF bug #2917219) - Added initial support to the Python client interface for specifying the encoding. - Fixed a bug in execute argument parsing in Python interface. - Added missing .sql files to the Windows installer. - In MonetDB/SQL, fixed bug in not(invalidtable). (SF bug #2927174) -- Sjoerd Mullender

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[MonetDB-users] OCaml-MonetDB is working.
by Guillaume Yziquel 22 Jan '10

22 Jan '10

Hello. I've managed to pull together, in my scarce free time, an OCaml binding for MonetDB. It is now working and I have written a very simple MAL client for an embedded database: > yziquel@seldon:~/git/ocaml-monetdb5$ utils/malclient.native > io.print(1); > 1 > io.print(2); > 2 I've got a small question concerning MAL. As I see it, MAL is currently a human-readable language. Is there somewhere in the MonetDB system a place where it is compiled to a more space-efficient representation? Or is interpreted as such? All the best, -- Guillaume Yziquel http://yziquel.homelinux.org/

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[MonetDB-users] MonetDB XQuery Bulk Load / Bulkload
by Alexander Koglin 21 Jan '10

21 Jan '10

I have currently installed a version of MonetDB XQuery for Linux and want to bulkload data like this: http://monetdb.cwi.nl/XQuery/Documentation/Bulk-Loading-a-Collection.html#B… For that purpose, I used the following command inside the Client: for $d in doc("/monetdbfiles.xml")//doc return pf:add-doc(fn:concat($d/@path,$d/@name), fn:string($d/@name), "abap10k", 0) <> It references the following, definitely existing XML file: <dir> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CCDEF"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CCIMP"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CCMAC"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CI"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CM001"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CM002"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CM003"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CM004"> <doc path="/home/epic/tarari_svn/benchmarks/abap/ABAP/" name="ACL_AUNIT_RESULT==============CM005"> </dir> But unfortunately an error is thrown (I also tried it unter Windows and it was the same): MAPI = root@localhost:50000 QUERY = for $d in doc("/monetdbfiles.xml")//doc ERROR = !ERROR: err:FODC0002, Error retrieving resource (no such document "/monetdbfiles.xml"). What could be the reason for that?

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[MonetDB-users] compression
by Jason Kinzer 20 Jan '10

20 Jan '10

Hi, Are there any plans on the horizon to roll compression into Monet? The X-100 project looked really interesting in this regard, but as I understand it, that work has been transferred into VectorWise. If there are no plans, is this because it's completely antithetical to the monet architecture (from the papers it seems like X-100 was, to some degree at least, 'integrated' in), or more due to lack of resources? My motivating example here is OLAP: I frequently have 1 relatively large fact table and then many much smaller dimensional tables. If optional compression were available, it we be nice to compress all or some of the BATs for the fact table columns and then have the others work as usual. (Well, at least this sounds good, maybe it makes no sense). Another motivation is there seems to be a lot of anecdotal evidence for companies moving from larger big iron servers to more numerous, smaller machines - so it would be really nice to have this capability for more memory constrained settings. I understand on a basic level how compression conflicts with the relatively simple approach monet uses to load BATs (e.g. memory map), but, dwelling in ignorance, I blithely assume there could be some solution not as complex as X-100 if one were to accept a significant performance cost. For example: decompressing BAT data on the fly as part of a BATiterator. I probably don't have the skills to implement even a basic on-the-fly decompression approach like this, but just wondering aloud: how hard a problem is this? Thanks, Jason

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[MonetDB-users] manually setting gdk_nr_threads to N?
by Nafees Ur Rehman 19 Jan '10

19 Jan '10

Hi, I am using Windows 2003 with two core processors configures, and the gdk_nr_threads does not show the 2nd processor. Can you tell me how can I set that manually? Regards Nafees Ur Rehman

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[MonetDB-users] Standard Deviation tips and hints request
by Dennis Forbes 17 Jan '10

17 Jan '10

Hi all. While it's possible to calculate the stddev with an aggregated cross join, is there perhaps a better way? Any tips or hints on where I should look? Can this be done in MIL or some other tactic to provide a more straightforward, better performing experience? I searched the web before asking and all I've found are unanswered questions, however I would really like to solve this even if it includes extending the system. Dennis W. Forbes Vastardis Capital Services 41 Madison Avenue, 30th Floor New York, NY 10010 P: 646-230-0933 F: 212-243-5251

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[MonetDB-users] mapi_query with MAL code?
by Guillaume Yziquel 17 Jan '10

17 Jan '10

Hello. I've been using an embedded SQL with moderate success with my OCaml binding. Essentially passing the SQL statement through the mapi_query() function call. I would now like to try out some MAL code in a similar setting: embedded MonetDB, code passed via mapi_query(). Could someone provide me with a simple "Hello world" MAL code to try? For now, all I've been able to achieve with MAL are segfaults... All the best, -- Guillaume Yziquel http://yziquel.homelinux.org/

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