- users-list - monetdb.org

[MonetDB-users] Question about used Encoding
by Markus Gritsch 04 Dec '07

04 Dec '07

Hi, I would like to know how encoding related issues are handles in MonetDB. For example, when I run the following Python script # -*- coding: utf-8 -*- import MonetSQLdb x = MonetSQLdb.connect(host = 'localhost', user = 'voc', password = 'voc', lang = 'sql') c = x.cursor() c.execute('DROP TABLE test') c.execute('CREATE TABLE test(id int, name varchar(20))') c.execute('INSERT INTO test (id, name) VALUES (%s, %s)', (0, 'ä ö ü')) c.close() x.close() and then look at the inserted data using DbVisualizer I get Ã¤ Ã¶ Ã¼ in the 'name' column. When I try to edit the value in the DbVisualizer, I get an error message "unexpected end of input". (The SQL statements reads update voc.test set name = 'ö' where id = 0). Is this a JDBC driver problem? When I connect to an MySQL database with the MySQL JDBC driver included in DbVisualizer I can insert arbitrary characters, and they get properly displayed in the GUI. Kind regards, Markus

3 29

[MonetDB-users] primary key retrieval
by Lange Marcus 04 Dec '07

04 Dec '07

Hello, How do I retrieve the primary key id value after inserting something new into the database ? I am writing a simple Java app. (using JDBC) and would like to get this info back into my program. Thanks for any help! Regards Marcus

2 2

[MonetDB-users] windows 127.0.0.1
by Miki Muzsi 04 Dec '07

04 Dec '07

Hi there, Anybody knows if the installation of Monet can be changed (on windows) to use localhost instead of 127.0.0.1. It seems that because of that I can not connect to MondetDB from a different machine; I get the error message: Could not open connection to the host, on port 50000: Connect failed. I've lokked into monetdb5.conf, registriey, docs ... nothing helpt. BTW I am using version v5.2.2 on windows. Cheers, Miki Chordiant Software International Ltd. Registered office: Chiswick Park Building 10, 566 Chiswick High Road, London W4 5XS Registered in UK no. 02155722 and VAT no. GB 479 9023 02 The information transmitted herewith is sensitive information of Chordiant Software or its customers and is intended only for use to the individual or entity to which it is addressed. If the reader of this message is not the intended recipient, you are hereby notified that any review, retransmission, dissemination, distribution, copying or other use of, or taking of any action in reliance upon, this information is strictly prohibited. If you have received this communication in error, please contact the sender and delete the material from your computer.

2 1

[MonetDB-users] offset support?
by m h 04 Dec '07

04 Dec '07

Is there support for OFFSET in queries? The syntax doesn't throw an error, but the expected behavior isn't correct... sql>select * from query_users; +---------+----------+ |user_id |user_name | +=========+==========+ | 1 |john | | 2 |jack | | 3 |ed | | 4 |wendy | | 5 |laura | | 6 |ralph | | 7 |fido | +---------+----------+ Timer 1.820 msec 7 rows sql> Timer 0.294 msec 0 rows sql>SELECT query_users.user_id, query_users.user_name more>FROM query_users ORDER BY query_users.user_id more> LIMIT 3 OFFSET 2; +---------+----------+ |user_id |user_name | +=========+==========+ | 1 |john | | 2 |jack | | 3 |ed | +---------+----------+ -matt

3 10

[MonetDB-users] Slow Data Load
by Paulo Jorge Dias 03 Dec '07

03 Dec '07

Hi, I am working on a Windows XP SP2 32bit with MonetDB v5.2.2 kernel v1.20.0 I have built a java program to upload data from an Oracle Database Table with 6milion rows. After about 4milion of rows loaded the performance decreases dramatically. I have tried to use other way, which is generating all insert statements to a file and then using mclient to execute all the insert statements. Slower that the java option because the autocommit=on and parsing of each statement, but the result is the same. After about 4milion of rows loaded the performance decreases dramatically. Can someone give an explanation for this behavior? Thanks, Paulo Jorge Dias -- View this message in context: http://www.nabble.com/Slow-Data-Load-tf4929292.html#a14108678 Sent from the monetdb-users mailing list archive at Nabble.com.

2 2

[MonetDB-users] Server in a weird state....
by m h 01 Dec '07

01 Dec '07

I tried running the SQLAlchemy ORM testsuite. The first time it ran for a while and then mserver segfaulted. (It also grew to using 700+Megs of memory. Am assumming this is a monetdb issue, since after each test the tables are usually dropped). The server now has issues. It appears to start fine: # MonetDB server v5.2.3, based on kernel v1.20.1 # Serving database 'demo' # Compiled for i686-pc-linux-gnu/32bit with 32bit OIDs dynamically linked # Copyright (c) 1993-2007 CWI, all rights reserved # Visit http://monetdb.cwi.nl/ for further information #warning: please don't forget to set your vault key! #(see /root/MonetDB/etc/monetdb5.conf) # Listening for connection requests on mapi:monetdb://127.0.0.1:50000/ # MonetDB/SQL module v2.20.3 loaded When I try to connect with the command line client it complains repeatedly: !ERROR: BUNdelete: access denied to tmp_537, aborting. !ERROR: BUNdelete: access denied to tmp_537, aborting. ....

3 21

[MonetDB-users] Preferred bulk load method?
by m h 01 Dec '07

01 Dec '07

Good afternoon- Just wondering if there is a preferred method to load large datasets into monetdb? Piping SQL through mclient? thanks much -matt

2 14

[MonetDB-users] Difficulty with External C Function
by Thomas J. Schulte 30 Nov '07

30 Nov '07

I'm having difficulty linking a custom external C function into MonetDB without crashing the database connection. If anyone knows of a documented end-to-end example of adding external functions compiled with GCC, please let me know. I've documented a minimal example below that crashes the connection for me each time. Software: Red Hat Linux knock-off CentOS, i386. Most recent MonetDB download from Sourceforge (server 5.2.2, client 1.20.2, common 1.20.0). GCC 4.1.1 1. Create a simple C file named te.c. int TEtest( ) { return 4; } 2. Compile file, move it to the proper directory, and create symlinks. $ gcc -c -fPIC te.c -o te.o $ gcc -shared -Wl,-soname,lib_te.so.0 -o lib_te.so.0.0.0 te.o (also tried with soname = libte.so.0, leaving output as lib_te.so.0.0.0) $ cp lib_te.so.0.0.0 $mhome/lib/MonetDB5/lib $ cd $mhome/lib/MonetDB5/lib $ ln -s lib_te.so.0.0.0 lib_te.so.0 $ ln -s lib_te.so.0.0.0 lib_te.so 3. Create a MAL file, saved as $mhome/lib/MonetDB5/te.mal module te; command test( ):int address TEtest(); command doesnotexist( ):int address TEdoesnotexist; 4. Update mal_init.mal by adding the following 2 lines: library te; include te; 5. Start a random DB and try to invoke the test function. Merovingian log show database dino killed by signal 11 afterwards. $ cd $mhome/bin $ ./merovingian & [1] xxxx $ ./mclient -lmal --database=dino -h COS1 mal> te.test( ); MAPI = monetdb@COS1:50001 ACTION= read_line QUERY = te.test(); ERROR = Connection terminated If I instead invoke te.doesnotexist(), I get a different error (below.) This leads me to think that MonetDB is findng and loading my compiled .so file, but it wasn't compiled correctly or otherwise isn't providing what MonetDB expects. mal> te.doesnotexist(); MAPI = monetdb@COS1:50001 QUERY = te.doesnotexist(); ERROR = !TypeException:user.main[1]:'te.doesnotexist' undefined in: _1:int := te.doesnotexist() Any pointers are appreciated. Thomas Schulte

3 2

[MonetDB-users] Howto query with non ascii in python?
by m h 30 Nov '07

30 Nov '07

How do I run non-ascii queries in python? Or from the command line for that matter? Naive tests on my part fail.... python: RuntimeError: !syntax error, unexpected IDENT, expecting INTERSECT or EXCEPT or UNION in: "select name from tables where system=false and name=unitéble2" commandline: sql>select name from tables where system=false and name=unitéble2; !syntax error, unexpected IDENT, expecting INTERSECT or EXCEPT or UNION in: "select name from tables where system=false and name=unitéble2" Thanks -matt

3 2

[MonetDB-users] incorrect handling of NULL values in "IN" statements?
by m h 29 Nov '07

29 Nov '07

My understanding that is that NULL is never equal to anything including itself. Thus to test for NULL values, one must use the IS operator. I'm wondering if the following is a bug. The NOT IN will return the null row, instead of the empty set. Are NULL values outside that query? CREATE TABLE query_users ( user_id INT NOT NULL AUTO_INCREMENT, user_name VARCHAR(20), PRIMARY KEY (user_id) ); INSERT INTO query_users (user_id, user_name) VALUES (1, 'matt'); INSERT INTO query_users (user_id, user_name) VALUES (2, 'fred'); INSERT INTO query_users (user_id, user_name) VALUES (3, null); SELECT user_name FROM query_users WHERE user_name IN ('matt', 'fred'); -- should return empty set, returns null SELECT user_name FROM query_users WHERE user_name NOT IN ('matt', 'fred');

2 3