March 2009 - users-list

[MonetDB-users] owner of files in dbfarm changed
by Ross Bates 16 Mar '09

16 Mar '09

Hi All - I've been running an Feb2009 nightly install for a few weeks now with no issues. Tried to start the database this morning and was getting tons of errors about the BACKUP directory, SQL Catalog, etc... It turns out that somehow various files dbfarm directory were changed to root ownership. Checked the system logs, bash history, etc.... and root hasn't been used to start any monetdb services or anything else related to monetdb. I know it sounds far fetched but is there something internal to the db which could have done this? Anyone seen mysterious ownership changes like this before? As for a solution, should I be ok just doing a chown on everything below my monetdb home back to the installation user? Thanks, Ross

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[MonetDB-users] [Fwd: making the server accessible from other machines]
by Martin Kersten 16 Mar '09

16 Mar '09

-------- Original Message -------- Subject: making the server accessible from other machines Date: Mon, 16 Mar 2009 11:59:29 +0100 From: francois guérin <replonk(a)gmail.com> To: monet(a)cwi.nl Hi, (i'm francois, this is not the first time i come to ask you some questions about monetdb...) i've tried to make the server accessible from another machine, but it dont work... when i launch the server, and enter the statement " xprc_trusted.delete(); ", everything's fine and i can access to my server with another machine. but, when i edit the MonetBD.conf file, as it's preconized in http://monetdb.cwi.nl/projects/monetdb/XQuery/Documentation/Security.html nothing change a quick look at my monetDB.conf file: # if not set port to address the HTTP server for pathfinder = mapi_port+1 xrpc_port="" # xrpc daemon is open for outside connections by default xrpc_open=yes # Additional options to be passed to the XRPC server, currently only # "timing". xrpc_options="" # IP addresses or hostname separated by ';' who can execute scripts in # <datadir>/MonetDB/xrpc/admin/ xrpc_admin="" # IP addresses or hostname separated by ';' who can retrieve XML # documents stored in the database using a URL of the form: # http://<host>[:port]/xrpc/<name>.xml xrpc_user="" # url prefixes of trusted modules separated by ';' xrpc_trusted="" As you can see, all slots are either open, either empty (that should mean any url/modules/user are allowed)

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Re: [MonetDB-users] import error in python script
by Ranadeeran 16 Mar '09

16 Mar '09

Yes i did that but didn't work.. > You should set PYTHONPATH to something like > /prefix/lib/python2.5/site-packages > > Can you confirm? > > Thanx, > Lazaros. > > On Thu, Mar 12, 2009 at 08:36:08PM +0530, Ranadeeran wrote: >> hi all >> i use MonetDB Database Server Toolkit v0.4 and ubuntu 8.10. >> im unable to issue any of the monetdb commands without prefixing them >> with >> a ./ >> that is instead of mserver5,it works only when i give ./mserver5 >> >> And im able to issue these commands only when im in the bin directory >> though i ve permanantly set the PATH variable in .bash_profile >> >> when i try to connect to monetdb using the sample python script that is >> given in the docs,i get an import error telling unable to import >> MonetDbSQL,though i ve set the PYTHONPATH variable to >> /prefix/lib/python2.5/site-packages/MonetDb directory >> >> the script is >> import MonetSQLdb >> # Let the cursor return dictionaries instead of tuples: >> # x = MonetSQLdb.connect(cursorclass = MonetSQLdb.cursors.DictCursor) >> x = MonetSQLdb.connect(host = 'localhost', user = 'monetdb',password = >> 'monet\db', lang = 'sql') >> #x = MonetSQLdb.connect(lang='sql') >> c = x.cursor() >> c.execute('select * from test') >> #print c.fetchone() >> print c.fetchall() >> x.close() >> >> But the script works fine on Debian Etch. >> >> i need to overcome these two issues... >> >> Thanks in advance, >> Mahesh >> ----------------------------------------- This email was sent using TCEMail Service. Thiagarajar College of Engineering Madurai - 625015 (India)

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[MonetDB-users] import error in python script
by Ranadeeran 13 Mar '09

13 Mar '09

hi all i use MonetDB Database Server Toolkit v0.4 and ubuntu 8.10. im unable to issue any of the monetdb commands without prefixing them with a ./ that is instead of mserver5,it works only when i give ./mserver5 And im able to issue these commands only when im in the bin directory though i ve permanantly set the PATH variable in .bash_profile when i try to connect to monetdb using the sample python script that is given in the docs,i get an import error telling unable to import MonetDbSQL,though i ve set the PYTHONPATH variable to /prefix/lib/python2.5/site-packages/MonetDb directory the script is import MonetSQLdb # Let the cursor return dictionaries instead of tuples: # x = MonetSQLdb.connect(cursorclass = MonetSQLdb.cursors.DictCursor) x = MonetSQLdb.connect(host = 'localhost', user = 'monetdb',password = 'monet\db', lang = 'sql') #x = MonetSQLdb.connect(lang='sql') c = x.cursor() c.execute('select * from test') #print c.fetchone() print c.fetchall() x.close() But the script works fine on Debian Etch. i need to overcome these two issues... Thanks in advance, Mahesh ----------------------------------------- This email was sent using TCEMail Service. Thiagarajar College of Engineering Madurai - 625015 (India)

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[MonetDB-users] Random errors and segfaults executing concurrent queries
by Dominique Prunier 12 Mar '09

12 Mar '09

Hi, I'm experiencing a lot of instabilities using MonetDB-Feb2009 on a moderately big database (70GB) with 3 concurrent (read only) connections. In my test setup, i have 3 identical tables which i query in parallel (from 3 jdbc connections). Almost every time, i get some weird errors: TypeException:user.s213_7[16]:'io.s13_4' undefined in: _26:any := io.s13_4() TypeException:user.s244_2[18]:'io.s14_6' undefined in: _31:any := io.s14_6() TypeException:user.s236_8[31]:'io.s18_3' undefined in: _47:any := io.s18_3() .... Finally, at some point, the server often segfault. Is there anything i can do to improve this ? Thanks,

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[MonetDB-users] Strange performance behavior on bulk import with / without sequences
by Cimballi 11 Mar '09

11 Mar '09

Hi, I have a strange behavior with MonetDB and the JDBC driver, maybe you have an explanation. Here is what I do : I import about 100 000 rows in MonetDB using the JDBC driver and simple SQL statements (not prepared) with Spring JDBC API. I made the test a first time using sequences, so before inserting the data I query for the next sequence number and then I insert the data. The second time, I generate the sequence number on the application side, using a simple increment, so I directly insert the data. And the strange result : In the first test, it took 7:30 minutes for the whole insert. In the second test, it took only 30 seconds for the whole insert. So, it seems there is a problem with the select performance, and in fact I saw this problem for another select operation. Do you have any idea about where it can come from ? Is there any configuration option or the way I use the JDBC API ? Thanks, Cimballi

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[MonetDB-users] writing out all fields
by dariuszs 11 Mar '09

11 Mar '09

Hi, Selecting 50 fields out of 300 takes almost no time to write out to csv file, but selecting everything takes forever - is there any setting that can improve the speed to write out all fields from a table? Thanks. Dariusz.

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[MonetDB-users] MonetDB-MAL usage questions
by Maria 10 Mar '09

10 Mar '09

Hi, I am having some problems using mal. firstly, I want to find bats of a table 'st' I loaded. I created a table 'st' using sql. > ./mclient -lsql -ddemo > \<simpletable.sql ==> it creates table 'st' with two columns 'id' and 'name' > \q then, I try to use mal. > ./mclient -lmal -ddemo > bbp.open(); > bbp.prelude(); > a := bbp.bind("st", "id"); then, I got following error msg > ERROR = !MALException:bbp.find:BAT not found I thought when a table is created using sql, it stored as number of bats and I can find it through bat buffer pool. but it seems that there is nothing in the bbp ( I tried bbp.getObjects(), and printed returns which contains no bats). Where can I get bats of table 'st'? What can be the logical name of each bat? (same as column name?? or tablename_columnname??) Second question) Although I've read all documents in MonetDB site, I'm still quite confused the way to use mal. For example, if I want to create table using mal, how could it be done? sql statement: "create table st ("id" integer not null, "name" varchar(30));" To understand mal, I think I need number of examples. Is there any documents I can study about mal? Is there any way to see system generated mal when I run sql statement? If I can, it can be good example code for me. I really hope that any one could help me. Thanks.

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Re: [MonetDB-users] too deep recursion
by Nils Grimsmo 09 Mar '09

09 Mar '09

Hi, I just upgraded from the Augst to the Noveber super-ball, and the performance has worsened badly. Example queries on dblp.xml (441 MB): Q0: count(/dblp//author[text()="Michael Stonebraker"]) Q1: count(/dblp/*/author[text()="Michael Stonebraker"]) Query time in milliseconds: August November Q0 1100 4867 Q1 3993 17999 I have compiled with --enable-optimise both times. I query with: mclient --language=xquery --algebra --time < $QUERYFILE Is this performance degradation expected? If so, why? BTW: Is there any way of finding how much disk space a collection uses? Thank you for contributing free software! Klem fra Nils -- http://www.idi.ntnu.no/~nilsgri/ Why is this thus? What is the reason of this thusness? - Artemus Ward

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[MonetDB-users] Kettle and MonetDB
by denvro 09 Mar '09

09 Mar '09

Hello, I have just installed Kettle 3.1 on my Archlinux machine. I wanted to use it with MonetDB but when i try to create a JDBC connection i get the following message: Error connecting to database [MonetDB] : org.pentaho.di.core.exception.KettleDatabaseException: Error occured while trying to connect to the database Error connecting to database: (using class nl.cwi.monetdb.jdbc.MonetDriver) Server challenge string unusable! Challenge contains too few tokens: !an internal error has occurred, please try again later I have merovingian running in the back and created a database "pentaho". See status below: bash-3.2# monetdb status -l pentaho pentaho: location: /usr/local/MonetDB/var/MonetDB5/dbfarm/pentaho database name: pentaho state: running locked: no scenarios: mal sql msql connections: mapi:monetdb://myhost:50001/ start count: 3 stop count: 2 crash count: 0 current uptime: 51m 10s average uptime: 13m 12s maximum uptime: 14m 42s minimum uptime: 11m 41s last crash: (unknown) last start: 2009-02-21 13:03:00 average of crashes in the last start attempt: 0 average of crashes in the last 10 start attempts: 0.00 average of crashes in the last 30 start attempts: 0.00 Can anybody help me with this. I already use the lates .jar (monetdb-1.9-jdbc). Kind Regards, Dennis -- View this message in context: http://www.nabble.com/Kettle-and-MonetDB-tp22141036p22141036.html Sent from the monetdb-users mailing list archive at Nabble.com.

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