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[Monetdb-developers] about implement some application interface
by kun ren 16 Aug '10

16 Aug '10

Dear all, My test application want to implement two application interface over MonetDB , one is loading *.csv file to MonetDB, to implement this interface ,I use MonetDB's JDBC and "copy from" command to implement it. and another interface is select from one bat using select conditions, such as this C function: bat *selectfrombat(char * batname,char * select condition), how do I implement it?do MonetDB has something like "copy from " command,and so I will use jdbc and the command to implement it? or other method to implement it? I know one MAL instruction is algebra.uselect, and corresponding C function, do I just use the C function or alter the C fuction? Best regards,

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[Monetdb-developers] Merge Tables MAL optimizer
by kun ren 13 Aug '10

13 Aug '10

dear all， Recently when I am reading MAL optimizer manual of MonetDB.and don't know the Merge Table optimizer,A merge association table (MAT). (1)How it perform optimize the MAL? (2) for this example, before optimize, m0:= bat.new(:oid,:int); m1:= bat.new(:oid,:int); m2:= bat.new(:oid,:int); b := mat.new(m0,m1,m2); s := algebra.select(b,1,3); i := aggr.count(s); io.print(s); io.print(i); c0 := bat.new(:int,:int); c1 := bat.new(:int,:int); c := mat.new(c0,c1); j := algebra.join(b,c); io.print(j); The selection and aggregate operations can simply be rewritten using a MAT: _33 := algebra.select(m0,1,3); _34 := algebra.select(m1,1,3); _35 := algebra.select(m2,1,3); s := mat.new(_33,_34,_35); i := 0:int; _36 := aggr.count(_33); i := calc.+(i,_36); Chapter 5: The MAL Optimizer 90 _37 := aggr.count(_34); i := calc.+(i,_37); _38 := aggr.count(_35); i := calc.+(i,_38); io.print(i); It seems that mat is very same with the bat.kunion, but what different between them, and how it optimizer the MAL? Best regards!

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[Monetdb-developers] about MAL optimize
by kun ren 11 Aug '10

11 Aug '10

Dear everyone, Recently,I am intersting in MAL optimize，and have read the manual of the MAL optimize, but it is so long, Possible if we want to use mal optimize ,we must degignation the optimize consideration, such as alias removal, constant expression,join path optimizer;And then I dedug the MonetDB,but default it don't use any optimize.so what do you think about the mal optimize? Best regards.

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[Monetdb-developers] About monetdb's thread
by kun ren 30 Jul '10

30 Jul '10

Dear all, hello,all, I download the windows installer of monetdb,and install,and then start MonetDB server, my computer has 4 cpus.and with 32bit windows xp ,but the MonetDB server only start one thread.when I run MonetDB in Linux with 2 cpus, it start 2 threads. so why? why I am in Windows xp with 4 cpus, it only create 1 thread ?

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[Monetdb-developers] need help for extracting BAT
by Gaetano Fabiano 29 Jul '10

29 Jul '10

Hi all, i'm a new user of MonetDB. I worked on MonetDB/SQL and I can use well it. Now I need to use MonetDB directly with MAL. But i'm not so able to do that. I run the client with this command on linux: mclient -lmal -d database So I can write MAL istruction. But I don't need to create a procedure in MAL that doesn't access to my data. What I need to do is that: I need to give the BAT data of my DataBase and put all data on my application: example C++ ora Java array, after that I need to manipulate this BAT with my application and update the original BAT. How can I do that? summarizing i need: - Access to the BAT of the table of my Database. - Print it on monitor - Put it in array, file, stack, or any DataStruct with any programming language. - Set my manipulated BAT again in MonetDB. All of this is possible? Someone can help me? I'm sorry if I don't know the netiquette of your mailing list but I need to do that and I don't know where I could be helped. Thanks. Gaetano.

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Re: [Monetdb-developers] MonetDB: Jun2010 - It seems the err output for the test was not ...
by Stefan Manegold 22 Jul '10

22 Jul '10

On Thu, Jul 22, 2010 at 11:53:22AM +0200, Romulo Goncalves wrote: > Changeset: 7a88e64c34b1 for MonetDB > URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=7a88e64c34b1 > Modified Files: > sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.err > sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.out > Branch: Jun2010 > Log Message: > > It seems the err output for the test was not complete. > In the approval of the test two sql statements were missing, therefore, the err output was created without the errors related to that two statements. Thanks for taking care of this. My reason for not approving the error messages in the first place was that I was not sure about the intention of the test, and hence, whether and which error messages are to be expected. I now understand from your approval that the error messages indeed match the intention of the test. I wonder, though, whether the error message is indeed what it should be. Saying "failed: Success" (see below) seems at least "odd" to me ... Stefan > > diffs (32 lines): > > diff -r 6908fb1d95e4 -r 7a88e64c34b1 sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.err > --- a/sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.err Thu Jul 22 11:02:07 2010 +0200 > +++ b/sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.err Thu Jul 22 11:53:14 2010 +0200 > @@ -71,9 +71,15 @@ > # 13:12:55 > mclient -lsql -ftest -i -e --host=rig --port=39884 > # 13:12:55 > > > -MAPI = monetdb@rig:39884 > +MAPI = monetdb@alviss:36310 > QUERY = connect to default; > ERROR = !CONNECT TO: DEFAULT is not supported! > +MAPI = monetdb@alviss:36310 > +QUERY = connect to 'whatever' port 50001 database 'nonexisting' USER 'monetdb' PASSWORD 'monetdb' LANGUAGE 'mal'; > +ERROR = !IOException:mapi.connect:Could not connect: gethostbyname failed: Success ^^^^^^ ^^^^^^^ !!!!!! ??????? > +MAPI = monetdb@alviss:36310 > +QUERY = disconnect 'whatever'; > +ERROR = !DISCONNECT CATALOG: no such db_alias 'whatever' > > # 13:12:55 > > # 13:12:55 > Done. > diff -r 6908fb1d95e4 -r 7a88e64c34b1 sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.out > --- a/sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.out Thu Jul 22 11:02:07 2010 +0200 > +++ b/sql/src/test/BugTracker-2010/Tests/connectto.Bug-2548.stable.out Thu Jul 22 11:53:14 2010 +0200 > @@ -23,8 +23,6 @@ > # 13:12:55 > mclient -lsql -ftest -i -e --host=rig --port=39884 > # 13:12:55 > > > -! to be provided / approved ! > - > # 13:12:55 > > # 13:12:55 > Done. > # 13:12:55 > > _______________________________________________ > Checkin-list mailing list > Checkin-list(a)monetdb.org > http://mail.monetdb.org/mailman/listinfo/checkin-list > -- | Dr. Stefan Manegold | mailto:Stefan.Manegold@cwi.nl | | CWI, P.O.Box 94079 | http://www.cwi.nl/~manegold/ | | 1090 GB Amsterdam | Tel.: +31 (20) 592-4212 | | The Netherlands | Fax : +31 (20) 592-4199 |

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[Monetdb-developers] about debug monetdb on windows
by kun ren 20 Jul '10

20 Jul '10

Dear everyone, Some days ago,I debug monetdb on linux ,use eclipse + gdb, but now I want to debug and compile the monetdb on windows, please tell me how would i will do to compile and debug the monetdb. Best regards!

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[Monetdb-developers] about copy command of Monetdb
by kun ren 20 Jul '10

20 Jul '10

Dear all, Recently,I use TPC-H test the Monetdb, On windows ,so I use "copy ,, records,,,into,,from" to load data to Monetdb,when the size of the file is about 700M,It is OK.But when the size is 1.4G,the Monetdb server is auto stop when loading. But when I am in Linux, it is no problem. So I want to ask why it is wrong on windows when the file is so large? Best regards,

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[Monetdb-developers] Announcement: New Jun2010-SP1 bugfix release of MonetDB suite
by Sjoerd Mullender 17 Jul '10

17 Jul '10

The MonetDB team at CWI/MonetDB BV is pleased to announce the Jun2010-SP1 bug fix release of the MonetDB suite of programs. Lots of problems have been fixed, the most important one being the fix in the handling of database upgrades of databases created with the Feb2010 release to the current version. More information (including release notes) on this release is available at <http://monetdb.cwi.nl/Development/Releases/Jun2010/>. The download location has changed to <http://dev.monetdb.org/downloads/>. Please fix any bookmarks you may have. -- Sjoerd Mullender

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Re: [Monetdb-developers] RDF data management in MonetDB/SQL
by wangx 17 Jul '10

17 Jul '10

Dear Lefteris, Thank you for your reply. Your explanation will help me much. In addition, would you give me some guidelines on how to make the 6 different indices of the triple table be understood by the SQL/SPARQL query optimizer and used accordingly. If I want to implement this feature by myself, in which files the code should be added or modified. BTW, in the future, will you implement the MonetDB/SPARQL as a new supported front-end language? Will you consider to translate SPARQL to MAL directly, instead of through SQL to MAL (but this way you have to develop a SPARQL specific optimizer, instead of making use of the SQL optimizer)? Thank you so much. Best regards, Xin Wang >From: Lefteris <lsidir(a)gmail.com> >Reply-To: >To: wangx <wangx(a)tju.edu.cn> >Subject: Re: [Monetdb-developers] RDF data management in MonetDB/SQL >Date:Fri, 16 Jul 2010 10:29:53 +0200 > >Hi, > >your understanding is in general correct. The availability of the six >different indices of the triple table should be understood by the >SQL/SPARQL query optimizer and used accordingly. However, the >MonetDB/RDF module has not been announced yet, and that is because it >has not finished yet. You are using a piece of code which is >experimental and unfinished. As such, the only way to test Monet and >its capabilities on RDF data is to manually write the SQL query in >such a way that you use the correct order of the triple table on the >correct join. > >In the future of course, this will be done by the optimizer and the >user will only have to write simple SPARQL queries referring to the >name of the graph, instead of the underlying storage schema, but until >then I am afraid you will have to do it by hand. The good news is that >if you are using RDF data and testing queries that have been published >previously on papers as benchmarks, most likely someone else will have >done already the translation to a correct SQL query (since most >experiments on newly build engines that do not support SPARQL use this >method). > >Hope this helps you a bit, > >lefteris > >2010/7/15 wangx : >> Hi MonetDB developers, >> I have a question about RDF data management in MonetDB/SQL. The comment of >> sql.rdfshred says "shredding an RDF data file from location results in 7 new >> tables (6 permutations of SPO and a mapping) ... We can then query with SQL >> queries the RDF triple store by quering tables gid_spo, gid_pso etc., ...". >> In my option, if the spo table is considered the triples table, the other 5 >> tables (sop, pso, pos, osp, ops) (except the mapping table) can be viewed as >> indexes of the triples table spo. >> When I writeSQLto query the shredded RDF data in the triples table, I >> have two ways.The first way is toonly use spo table tomake self-joins. >> The second way is touse all 6 tables to make joins. I noticed that >> "MonetDB/SQL Reference Manual" says that "The heart is the MonetDB server, >> which comes with the following innovative features. ... Index selection, >> creation and maintenance is automatic". IfI use6 tables (as indexes) >> explicitly to make joins, it seems that I write the query plan by myself. >> However, I think this work should be done by the SQL optimizer using >> statistics from the system catalog. I wondered if these tables have >> alreadybeen specified as indexes in the internal code, or if there is a way >> to specify it so that the optimizer can use them as indexes to generate >> query plans. I am not sure if my understanding is correct. I will appreciate >> any help from developers. Thank you in advance. >> >> Best regards, >> Xin Wang >> ------------------------------------------------------------------------------ >> This SF.net email is sponsored by Sprint >> What will you do first with EVO, the first 4G phone? >> Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first >> _______________________________________________ >> Monetdb-developers mailing list >> Monetdb-developers(a)lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/monetdb-developers >> >> >

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