- 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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[MonetDB-users] Data compression in MonetDB
by Ken Cheng 18 Jun '11

18 Jun '11

Hi All, I am going to build a DW based on MonetDB. After check on the internet I found that MonetDB does not do data compression. Same data set in MonetDb is much bigger than MySQL and infoBright. Are there any plan to do data compression in the MonetDB? Yours sincerely, Ken Cheng

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[MonetDB-users] Windowing functions ?
by Fabian Pijcke 16 Jun '11

16 Jun '11

Hello everyone, After visiting the MonetDB website, I didn't saw any information about the windowing functions of SQL (ranking, selecting max according to a defined order, etc.) A (very) short introduction can be found on wikipedia: http://en.wikipedia.org/wiki/Select_%28SQL%29#Window_function I know it is implemented into PostGreSQL, Oracle and Microsoft SQL Server. Is there any chance to see this function in MonetDB in the future ? Thanks in advance, sorry for my poor english ... :( Fabian Pijcke

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[MonetDB-users] Create Database - Load Data
by Lowterm 15 Jun '11

15 Jun '11

Hi, how can I create a new Database under Windows and how can I load data in a table form a external file? Thanks -- View this message in context: http://old.nabble.com/Create-Database---Load-Data-tp31653813p31653813.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] PhD position at CWI Database Architecture group
by Stefan Manegold 14 Jun '11

14 Jun '11

CWI is an internationally renowned research institute in mathematics and computer science, located in Amsterdam, The Netherlands. The focus is on fundamental research problems, inspired by societal needs. Research is carried out in 18 research groups and a substantial fraction is carried out in the framework of (inter)national programs. VACANCY CWI has a vacancy for a talented PhD candidate in the DB Architectures group (http://www.cwi.nl/en/research-groups/Database-Architectures) DISTRIBUTED DATABASE ARCHITECTURES FOR SCIENCE APPLICATIONS 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. The group has a unique methodology that combines fundamental database research with active participation of all group members in database engineering, centered around the open-source analytical database system MonetDB (http://www.monetdb.org/) You will be expected to write both papers and contribute to this code base. The focus of the group is on hard core data management and for this position specifically on database architectures to support large scale scientific applications in the context of the SciLens project (http://www.scilens.org) The goal is to leverage the potential power of a 330 node dedicated database machine to improve science in, e.g., astronomy and seismology. (http://www.scilens.org/content/platform) CWI maintains excellent relations with industry and the academic world, both in the Netherlands as well as abroad. An internship at one of the partnering database research labs world-wide is considered part of the PhD track. After their research careers at CWI, many staff members find employment in these sectors or in spin-off companies based on research results from CWI. Of course, library and computing facilities are first-class. 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. REQUIREMENTS The PhD candidates must have a master degree in computer science, (specialization distributed systems, database, software engineering) mathematics, or related fields. Preferable qualifications for candidates include proven research talent, system programming skills (C/C++), practical experience with database systems, and software development in a team. One should bring good academic writing and presentation skills. Candidates are expected to have an excellent command of English. TERMS AND CONDITIONS The terms of employment are in accordance with the Dutch "CAO-onderzoeksinstellingen". Moreover, CWI offers attractive working conditions, including flexibility and help with housing for foreigners. The gross monthly salary (on a full time basis) will be â¬ 2,037 during the first year and will reach â¬ 2,610 during the fourth year. INFORMATION Additional information can be obtained from prof.dr. Martin Kersten, email martin.kersten(a)cwi.nl, telephone +31(0)20 592 4066, or dr. Stefan Manegold, email stefan.manegold(a)cwi.nl, telephone +31(0)20 592 4212. -- | Stefan.Manegold @ CWI.nl | DB Architectures (INS1) | | http://CWI.nl/~manegold/ | Science Park 123 (L321) | | Tel.: +31 (0)20 592-4212 | 1098 XG Amsterdam (NL) |

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[MonetDB-users] Select Query crashes the server with "--single-user" option
by Ramak 13 Jun '11

13 Jun '11

Hi, I am trying to use MonetDB in single user mode. While I could load the data using "COPY INTO" command and run a few select queries successfully, the moment i run a query with group by on more than one column, the server crashes saying " ---- >Segmentation fault". Is there a way to get around it? or, am I using it the wrong way? I could recreate the problem doing this--- 1. Start server with "sudo mserver5 --dbfarm='/home/user/work/tmp/data/test' --single-user" 2. start mclient (and create a simple table and fire a select query with group by on multiple columns) >create table test ( market_size int not null, market int not null, state int not null); >select count(*) from test group by market_size, state; -- server crashes on the above query. I am using MonetDB 5 server v11.3.3 "Apr2011-SP1" (64-bit, 64-bit oids) Thanks, Ram -- View this message in context: http://old.nabble.com/Select-Query-crashes-the-server-with-%22--single-user… Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Production Database Crash - Analysis / Recovery?
by Philippe Hanrigou 12 Jun '11

12 Jun '11

My database is crashing quite systematically in production during some data import (which is in the form as a serie of DELETE ... WHERE / COPY INTO). The relevant information from the merovigian.log seems to be: 2011-06-02 04:53:27 MSG prod_reporting[25449]: !SQLException:SQLinit:Catalogue initialization failed 2011-06-02 04:53:27 MSG prod_reporting[25449]: !ERROR: HEAPextend: failed to extend to 3316460814336 for 11/40/114026theap A) What does this error mean? ----------------------------------------- A lack of memory? I am quite confused as the entire database is barely 5G on disk and there is 7G of RAM on this machine, which is dedicated solely to MonetDB. Moreover I only DELETE/COPY INTO in a single table at a time and the biggest table is barely 1.6G. Cleary there is some memory dynamic that I am not understanding. B) How do I recover the crashed database? ----------------------------------------------------------- It would not start anymore: 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Listening for UNIX domain connection requests on mapi:monetdb:///var/monetdb5/dbfarm/prod_reporting/.mapi.sock 2011-06-02 04:55:19 MSG prod_reporting[1665]: # MonetDB/SQL module loaded 2011-06-02 04:55:19 MSG merovingian[1644]: database 'prod_reporting' (1665) was killed by signal SIGSEGV 2011-06-02 04:55:29 ERR control[1644]: (local): failed to fork mserver: database 'prod_reporting' has crashed after starting, manual intervention needed, check merovingian's logfile for details Thanks in advance, - Philippe -- more complete extract from merovigian.log --- 2011-06-02 04:40:38 MSG merovingian[639]: proxying client ip-10-204-61-105.ec2.internal:52864 for database 'prod_reporting' to mapi:monetdb:///var/monetdb5/dbfarm/prod_reporting/.mapi.sock?database=prod_reporting 2011-06-02 04:40:38 MSG merovingian[639]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying 2011-06-02 04:53:09 MSG control[639]: (local): served status list 2011-06-02 04:53:23 MSG merovingian[639]: caught SIGTERM, starting shutdown sequence 2011-06-02 04:53:24 MSG control[639]: control channel closed 2011-06-02 04:53:27 MSG merovingian[639]: sending process 25449 (database 'prod_reporting') the TERM signal 2011-06-02 04:53:27 MSG prod_reporting[25449]: !SQLException:SQLinit:Catalogue initialization failed 2011-06-02 04:53:27 MSG prod_reporting[25449]: !ERROR: HEAPextend: failed to extend to 3316460814336 for 11/40/114026theap 2011-06-02 04:53:27 MSG merovingian[639]: database 'prod_reporting' (25449) has exited with exit status 0 2011-06-02 04:53:27 MSG merovingian[639]: database 'prod_reporting' has shut down 2011-06-02 04:53:27 MSG merovingian[639]: Merovingian 1.4 stopped 2011-06-02 04:55:16 MSG merovingian[1644]: Merovingian 1.4 (Apr2011-SP1) starting 2011-06-02 04:55:16 MSG merovingian[1644]: monitoring dbfarm /var/monetdb5/dbfarm 2011-06-02 04:55:16 MSG merovingian[1644]: accepting connections on TCP socket 0.0.0.0:50000 2011-06-02 04:55:16 MSG merovingian[1644]: accepting connections on UNIX domain socket /tmp/.s.monetdb.50000 2011-06-02 04:55:16 MSG discovery[1644]: listening for UDP messages on 0.0.0.0:50000 2011-06-02 04:55:16 MSG control[1644]: accepting connections on UNIX domain socket /tmp/.s.merovingian.50001 2011-06-02 04:55:16 MSG control[1644]: accepting connections on TCP socket 0.0.0.0:50001 2011-06-02 04:55:16 MSG discovery[1644]: new neighbour ip-10-32-111-2 (ip-10-32-111-2.ec2.internal) 2011-06-02 04:55:16 MSG discovery[1644]: new database mapi:monetdb://ip-10-32-111-2:50000/prod_reporting (ttl=660s) 2011-06-02 04:55:16 MSG discovery[1644]: registered neighbour ip-10-32-111-2:50001 2011-06-02 04:55:19 MSG control[1644]: (local): served status list 2011-06-02 04:55:19 MSG merovingian[1644]: starting database 'prod_reporting', up min/avg/max: 1m/31m/1h, crash average: 0.00 0.10 0.03 (6-5=1) 2011-06-02 04:55:19 MSG prod_reporting[1665]: arguments: /usr/bin/mserver5 --set gdk_dbfarm=/var/monetdb5/dbfarm --dbname=prod_reporting --set merovingian_uri=mapi:monetdb://ip-10-32-111-2:50000/prod_reporting --set mapi_open=false --set mapi_port=0 --set mapi_usock=/var/monetdb5/dbfarm/prod_reporting/.mapi.sock --set monet_vault_key=/var/monetdb5/dbfarm/prod_reporting/.vaultkey --set monet_daemon=yes 2011-06-02 04:55:19 MSG prod_reporting[1665]: # MonetDB 5 server v11.3.3 "Apr2011-SP1" 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Serving database 'prod_reporting', using 2 threads 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Compiled for x86_64-pc-linux-gnu/64bit with 64bit OIDs dynamically linked 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Found 7.294 GiB available main-memory. 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Copyright (c) 1993-July 2008 CWI. 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Copyright (c) August 2008-2011 MonetDB B.V., all rights reserved 2011-06-02 04:55:19 MSG prod_reporting[1665]: # Listening for UNIX domain connection requests on mapi:monetdb:///var/monetdb5/dbfarm/prod_reporting/.mapi.sock 2011-06-02 04:55:19 MSG prod_reporting[1665]: # MonetDB/SQL module loaded 2011-06-02 04:55:19 MSG merovingian[1644]: database 'prod_reporting' (1665) was killed by signal SIGSEGV 2011-06-02 04:55:29 ERR control[1644]: (local): failed to fork mserver: database 'prod_reporting' has crashed after starting, manual intervention needed, check merovingian's logfile for details 2011-06-02 05:03:18 MSG merovingian[1644]: database 'prod_reporting' has crashed after start on 2011-06-02 04:55:19, attempting restart, up min/avg/max: 1m/31m/1h, crash average: 1.00 0.20 0.07 (7-5=2)

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[MonetDB-users] monetdb checkpoint
by Philippe Hanrigou 11 Jun '11

11 Jun '11

Hi, Online documentation at http://www.monetdb.org/Documentation/Cookbooks/ServerMgmt/ResourceLimits mentions: > The database checkpoint can be made using 'monetdb checkpoint' Yet checkpoint does not seem to be a valid monetdb command. Is it a typo, an historical vestige? Cheers, - Philippe

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[MonetDB-users] Octopus usage in MonetDB
by Andrei Cojocaru 07 Jun '11

07 Jun '11

Hi all, I am trying to setup (and play around with) a MonetDB-Apr11 cluster since the dataset I am expecting to have is beyond what can fit in the memory one node (starting with at least a few hundred gigabytes). I have been following the instructions athttp://www.monetdb.org/Documentation/Cookbooks/Recipes/Cluster and have a few nodes setup. I ran all the commands given there on all the nodes except for the creation of the master database which I ran on only the master. Also, I set the pipe to octopus_pipe on the master database. In mclient, I ran the following commands (from the sample squid test for octopus in the MonetDB source code): create table squidA( Bid int, Cval int); create table squidD( Eid int, Fval int); -- let's fill the tables create procedure fill(lim int) begin declare i int; set i = 0; while i < lim do insert into squidA values(i,rand()); insert into squidD values(i,rand()); set i = i+1; end while; end; declare size int; set size=100; call fill(size); It all runs with no errors. However, when I run: select Bid from squidA, I get a screenful of errors. They are all a variation of: TypeException:octopus.tentacle_3_11[6]:'octopus.bind' undefined in: _18:bat[:oid,:int] := octopus.bind(_2:str, _8:str, _9:str, _13:str, _19:int, _16:int, _17:int, version:int) Would you be able to offer some guidance on how to get this running? I was considering setting up application level partitioning and run multiple MonetDB instances directly, but if octopus does a lot of that work I would prefer to save myself the development and debugging time. Thanks for any help you could provide. -Andrei

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[MonetDB-users] Problem with Create Tables
by Lowterm 03 Jun '11

03 Jun '11

Hi, what's the meaning of this syntax error? Syntax error, unexpected CREATE, expecting SCOLON in: "create ..." I get this message with the "create table" if I load a Files with "sql>\< filename", which contains this statement. The create-statement works, if I insert it directly. The second error message ist: syntax error, unexpected ON, expecting ')' or ',' in: "create ..." in the following create statement: CREATE TABLE dim_warehouse ( is_current smallint NOT NULL, last_modified timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ) but I can not see wath is wrong. Thanks -- View this message in context: http://old.nabble.com/Problem-with-Create-Tables-tp31757411p31757411.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Aggregating by a computed field?
by Synaptic Axon 01 Jun '11

01 Jun '11

Hello, I recently install MonetDB and have been trying to get a feel for its speed and storage. I ran into an issue with SELECT queries trying to GROUP BY a computed field. For example, imagine a table like this: CREATE TABLE foo ( ts TIMESTAMP NOT NULL, category VARCHAR(32) NOT NULL ); I want to count the number of categories by year, so I want to craft a query like this: sql> SELECT EXTRACT( year from ts ) as year, category, COUNT(category) FROM foo GROUP BY 1, 2 ORDER BY 3 DESC; syntax error, unexpected sqlINT in: "SELECT EXTRACT( year from ts ) as year, category, COUNT(category) FROM foo GROUP BY 1, 2 ORDER BY 3 DESC" Unfortunately, MonetDB does not appear to support positional fields in the GROUP BY clause. So I tried rewriting it like this: sql> SELECT EXTRACT( year from ts ) as year, category, COUNT(category) FROM foo GROUP BY EXTRACT( year from ts ), category ORDER BY 3 DESC; syntax error, unexpected EXTRACT in: "SELECT EXTRACT( year from ts ) as year, category, COUNT(category) FROM foo GROUP BY EXTRACT( year from ts ), category ORDER BY 3 DESC" Ok, how about using "year" instead of the extract( .. ) bit? sql> SELECT EXTRACT( year from ts ) as year, category, COUNT(category) FROM foo GROUP BY year, category ORDER BY 3 DESC; syntax error, unexpected YEAR in: "SELECT EXTRACT( year from ts ) as year, category, COUNT(category) FROM foo GROUP BY year, category ORDER BY 3 DESC" What is the correct way to group by the computed field? Should I create a view? Is there a positional syntax for the GROUP BY clause I am overlooking? $ monetdb --version MonetDB Database Server Toolkit v0.8 (Apr2011) $ monetdbd --version MonetDB Database Server v1.4 (Apr2011) $ mclient --version mclient, the MonetDB interactive terminal (Apr2011) support for command-line editing compiled-in Thank you.

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[MonetDB-users] Announcement: New Apr2011-SP1 bugfix release
by Fabian Groffen 31 May '11

31 May '11

The MonetDB team at CWI/MonetDB BV is pleased to announce the Apr2011-SP1 bugfix release of the MonetDB suite of programs. At the time of this release, we also officially changed to our new website at http://www.monetdb.org/. This new website is our central source of information, and comes with our new logo and style. For details on this release, please see the release notes at <http://www.monetdb.org/Downloads/ReleaseNotes>.

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[MonetDB-users] Syntax for column tables
by Michael K 25 May '11

25 May '11

Hi, is there a "CREATE COLUMN TABLE xyz" like statement in MonetDB or will every "CREATE TABLE" create a column table? Can I create "normal" row store tables in MonetDB at all? I have read http://monetdb.cwi.nl/SQL/Documentation/Table-Definition.htmlbut did not found the information I was looking for. Kind regards. michael

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[MonetDB-users] mclient credentials after install?
by Philippe Hanrigou 22 May '11

22 May '11

Hi, I am trying to get started with MonetDB in order to assess its response time for an in-house dataset. I managed to configure/make/install it on my MacBook Pro (I have joined the custom Portfile I used for this purpose at the end of this email in case it matters). Nevertheless, when I go through the "Getting started" instructions, mclient is asking for credentials that I never had a chance to explicitly set: ph7:~$ monetdbd start ph7:~$ monetdbd get all property value hostname Solaris.local dbfarm /opt/local/var/monetdb5/dbfarm mserver /opt/local/bin/mserver5 logfile merovingian.log pidfile merovingian.pid sockdir /tmp port 50000 controlport 50001 discoveryport 50000 exittimeout 60 forward proxy discoveryttl 600 passphrase <unknown> mapisock /tmp/.s.monetdb.50000 controlsock /tmp/.s.merovingian.50001 ph7:~$ monetdb create demo created database in maintenance mode: demo ph7:~$ monetdb status name state uptime health last crash demo locked ph7:~$ monetdb release demo taken database out of maintenance mode: demo ph7:~$ monetdb status name state uptime health last crash demo stopped ph7:~$ mclient -d demo user(ph7): password: InvalidCredentialsException:checkCredentials:invalid credentials for user 'ph7' Which credentials am supposed to use to launch mclient? I am willing to try any workaround as, at this point, I am not concerned with security at all. Thanks in advance, - Philippe --------------------------------------------------------- # ph7's custom Portfile # $Id PortSystem 1.0 name MonetDB version 11.3.1 categories databases platforms darwin maintainers nomaintainer description MonetDB is an open-source database system for high-performance applications in data mining, OLAP, GIS, XML Query, text and multimedia retrieval. MonetDB often achieves a significant speed improvement for SQL and XQuery over other open-source systems. homepage http://www.monetdb.org master_sites http://dev.monetdb.org/downloads/sources/Latest/ distfiles MonetDB-${version}.tar.bz2 use_bzip2 yes checksums md5 f48869c87a56604d1c06f7d8243554f9 \ sha1 03a29a5e00a90d5294443ffb849167a2c108302e \ rmd160 c9bcdff333a60aad42dc8504c458335494e749f1 configure.args --enable-debug=no --enable-assert=no --enable-optimize=yes

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[MonetDB-users] using MonetDB in embedded mode - mapi interface
by Ramak 21 May '11

21 May '11

Hi, I am trying to use monetDB in embedded mode. The sample at "http://monetdb.cwi.nl/SQL/Documentation/A-Simple-Example.html#A-Simple-Exam…" suggests that we can interface to the data base using "embedded_sql()" method in combination with "embeddedclient.h". I dont seem to find this method in the library "libmapi.so.3"; neither the include file in the code base. Is "embedded mode" still supported? is there an alternate way of connecting to embedded monetDB server? PS: I am using monedDB5 - April 2011 release. Thanks, Ram -- View this message in context: http://old.nabble.com/using-MonetDB-in-embedded-mode---mapi-interface-tp316… Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] Does a primary key based on a single column + numeric improve performance in MonetDB?
by Philippe Hanrigou 20 May '11

20 May '11

Hi, I am designing the schema of our brand new MonetDB database, and I am not sure whether my previous data modeling instincts are still relevant ;-). In particular, I am wondering: A) Does the definition of primary keys / foreign keys improve MonetDB performance? B) I need to do joins with a table whose natural key which is the combination of (bigint, varchar(51)). Is it best to: 1) just add these 2 columns to the dependent tables, and join on these 2 columns. 2) create a single varchar column that would be the concatenation of the bigint + varchar(51) and join on this single varchar column 3) Introduce a numeric+sequential surrogate key (presumably generated from a sequence), and join on the surrogate key. I am especially interested in the performance / acidental complexity tradeoffs in this situation. Thanks in advance, - Philippe

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