- users-list - monetdb.org

[MonetDB-users] Problem with Create Function sintaxis
by elarios＠liacs.nl 20 Jul '11

20 Jul '11

Hi, I'm using MonetDB over Fedora 15 and the driver monetdb-1.20-jdbc.jar I have problems with the sintaxis of the following function: ----------------------- create function hts.Get_idimage() returns int begin declare idimag int; select max(Imag_id) into idimag from hts.Image; returns idimag+1; end; ----------------------- the error message is: ----------------------- Error: syntax error, unexpected $end, expecting WHILE in: "create function hts.get_idimage() returns int begin declare idimag int;" SQLState: null ErrorCode: 0 Error occured in: create function hts.Get_idimage() returns int begin declare idimag int ----------------------- Can you give me some clues of how to fix this sintaxis error? I've checked the SQL 2003 framework and the script looks fine. Thanks in advance for your help. Enrique.

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[MonetDB-users] Table with 1 000 000 000 rows
by Eugene Prokopiev 20 Jul '11

20 Jul '11

Hi, is it possible to store 1 000 000 000 rows in one table or I need to use some partitioning algorithm? -- Thanks, Eugene Prokopiev

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[MonetDB-users] Normalization
by Eugene Prokopiev 20 Jul '11

20 Jul '11

Hi, need I use normalization for tables in colum-oriented databases or it will only decreses perfomance without reducing space usage and other advantages? -- Thanks, Eugene Prokopiev

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[MonetDB-users] Information about Loader
by Lowterm 19 Jul '11

19 Jul '11

Hi, I need some information about MonetDB Loader. Where can I find it? Is there any documentation about it? Thanks -- View this message in context: http://old.nabble.com/Information-about-Loader-tp32084241p32084241.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Clustering, Replication, MultiThreading, Restore
by joel vennin 10 Jul '11

10 Jul '11

Hi, I've just discover MonetDB. I've found some documentation but i've still some questions. 1) About replication, i'm unable to find a documentation about replication support inside MonetDB, if it is not supported do you plan to support it natively, or is there some special script to launch in order to have database in sync. 2) About clustering, my understanding about clustering is to allow one client to launch a sql query on a database through merovingian (if i understood). The query is analysed by all nodes of the cluster and then it return the answer. However, it seems it is not the case, if I follow the documentation on the website about clustering, it seems that I will be connected through a round robin fashion to one of the node. Once connected my query will be executed only on that node. 3) About multithreading, I mean multi query execution per user, I think MonetDb support the fact that multi user can connect to the database and launch different query on it. But is it possible to configure the number of concurrent connection, to setup the number of thread that handle queries ? 4) If MonetDb crash, is it possible that db files become corrupted ? In this case, is there a script to fix it ? Thank you for your help Joel

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[MonetDB-users] how store tiff image in monet db?
by rose26 08 Jul '11

08 Jul '11

-- View this message in context: http://old.nabble.com/how-store-tiff-image-in-monet-db--tp32014566p32014566… Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Installation problem in Fedora 15
by elarios＠liacs.nl 06 Jul '11

06 Jul '11

Hi, I'm interested in using MonetDB in my project and I'm a beginner in this topic, so I'm sorry for the silly questions that I can make. The problem is: I'm trying to install MonetDB-SQL Server in Fedora 15, but when I execute the command: yum install MonetDB-SQL-server5 MonetDB-client The output makes reference to a repository that doesn't exist: http://dev.monetdb.org/downloads/Fedora/15/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found : http://dev.monetdb.org/downloads/Fedora/15/x86_64/repodata/repomd.xml Trying other mirror. http://dev.monetdb.org/downloads/Fedora/15/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found : http://dev.monetdb.org/downloads/Fedora/15/x86_64/repodata/repomd.xml Trying other mirror. Error: Cannot retrieve repository metadata (repomd.xml) for repository: monetdb. Please verify its path and try again Should I downgrade my operating system to Fedora 14? Do you have any suggestions? Thanks for your time and help, Best regards, Enrique.

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[MonetDB-users] PhD opening at CWI - Adaptive indexing techniques for modern database systems
by Stratos Idreos 23 Jun '11

23 Jun '11

Subject: Adaptive indexing techniques for modern database systems. The Centrum Wiskunde & Informatica (CWI) has a full time vacancy for a talented PhD candidate in the Database Architectures group (http://www.cwi.nl/en/research-groups/Database-Architectures) The position is in the broad area of adaptive indexing techniques for modern database systems. Adaptive indexing is a major challenge in database research; it tries to completely alleviate the need for indexing and tuning steps leading to database systems that require no physical design set-up and can cope immediately with any workload. This leads to database systems that are instantly usable and thus more applicable to numerous new applications that now consider databases too slow, too complex and too old. This position will focus specifically on adaptive indexing for extremely large databases where traditional indexing represents a major bottleneck. The Database Architectures group is one of the world-wide leading groups in system-oriented database research, e.g., it received the 10-year best paper award at VLDB 2009 for their pioneering research on hardware-aware database technology and the column-store model and the 2011 ACM SIGMOD Jim Gray Dissertation award for the database cracking work. The group has a unique methodology that combines fundamental database research with active participation of all group members in database engineering, centred around the open-source analytical database system MonetDB (http://www.monetdb.org/) An internship at one of the partnering database research labs world-wide is considered part of the PhD track. REQUIREMENTS The PhD candidates must have a master degree in computer science (or a 5 year diploma), (specialisation databases, distributed systems, software engineering) mathematics, or related fields. Preferable qualifications for candidates include proven research talent, system programming skills (C/C++), practical experience with using and implementing database systems, and software development in a team. Candidates are expected to have an excellent command of English, and good academic writing and presentation skills. CENTRUM WISKUNDE & INFORMATICA (CWI) Founded in 1946, the Centrum Wiskunde & Informatica (CWI) is the national research institute for mathematics and computer science in the Netherlands. It is located at the Science Park Amsterdam and is part of the “Netherlands Organisation for Scientific Research” (NWO). The institute is internationally focused and renowned for its high quality research, a substantial fraction of which is carried out in the framework of (inter)national programs. Over 160 researchers conduct pioneering research and share their acquired knowledge with society. More than 30 researchers are employed as professors at universities. The institute has generated twenty-one spin-off companies. CWI maintains excellent relations with industry and the academic world, both in the Netherlands as well as abroad. After their research careers at CWI, an increasing number of young staff members find employment in these sectors or in spin-off companies that are based on research results from CWI. Of course, library and computing facilities are first-rate. CWI's non-scientific services to its personnel include career planning, training and courses, assistance in finding housing, and tailor-made solutions to problems that may occasionally arise. TERMS AND CONDITIONS The terms of employment are in accordance with the Dutch Collective Labour Agreement for Research Institutes ("CAO-onderzoeksinstellingen"). Moreover CWI offers attractive working conditions, including flexible scheduling and help with housing for expat employees. The gross monthly salary, for an employee on a full time basis, is €2,037 during the first year and increases to €2,610 over a four year period. CWI also offers excellent and flexible terms of employment, including an employee pension fund. INFORMATION Additional information can be obtained from: dr. Stratos Idreos, email stratos.idreos(a)cwi.nl, telephone +31(0)20 592 4169. or dr. Stefan Manegold, email stefan.manegold(a)cwi.nl, telephone +31(0)20 592 4212, or prof. dr. Martin Kersten, email martin.kersten(a)cwi.nl, telephone +31(0)20 592 4066. APPLICATION Please send your application before 31 July 2011 to: pd(a)cwi.nl. Applications should include a detailed CV, a motivation letter, a list of your M.SC. courses and grades, a copy of your master thesis, and preferably a list of publications.

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[MonetDB-users] Parallelization
by Michael Kusber 20 Jun '11

20 Jun '11

Hi, I'm playing with parallization of databases and I am a little confused about my result on MonetDB. Scenario: 15 Millions of Entries and i want to find the number of entries where the attributes are in a certain sector (i know, a simple select would do the work but i wanted a simple example) i have java code that get all 15 Mio. Data from the database via JDBC and iterates over them with a loop without multithreading. --> 13 ms then i created a stored function: CREATE FUNCTION isInRangexy(x DECIMAL(10,7), y DECIMAL(10,7)) RETURNS BOOL BEGIN ATOMIC IF x > 50 AND y < 50 THEN RETURN true; ELSE RETURN false; END IF; END Then I call it with: SELECT COUNT(*) FROM location WHERE isInRange(x,y) It works, but it is more than 3 times slower than the first java option. I had thought i would get benefit from the fact that i don't need to transfer all the data to the application and of some parallelization and other optimization from monetdb. Did I made a mistake? Can I use another example to get the anticipated results? thanks, michael

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[MonetDB-users] Stored procedures
by Michael Kusber 19 Jun '11

19 Jun '11

Hi, is it possible to achieve the following using SQL stored procedures à la "CREATE PROCEDURE XYZ"? I want to write a function that iterates over a table and adds 2 on a certain attribute. i am realizing that i could do this by an UPDATE, but I wanted to see, whether it would be executed more parallel inside a stored procedure. Is there a way of formulating this in a procedure? do i need to define a function in MAL? would this result in more parallel execution? thanks, michael

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