- users-list - monetdb.org

[MonetDB-users] MonetDb slowing down
by Cory Isaacson 07 Sep '12

07 Sep '12

We have MonetDb running in the AWS cloud, with about 32GB of physical RAM. Our process uses COPY INTO every few minutes to load small chunks of data (usually 1000 rows at a time). That seems to work fine. There are a few users running queries against MonetDb, and now at least once/day we have to start/stop MonetDb. We see very high disk I/O (mainly I/O wait), so it appears that memory usage is high and does not get released. We are using the April 2012 release. The JDBC client is used for these queries. Overall MonetDb is doing a very good job, but this slowdown makes it appear unstable to end users. If there are any suggestions on how to improve this please let us know. cmi --

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[MonetDB-users] Connecting from DBLite.com
by Medha Atre 06 Sep '12

06 Sep '12

Hello, I have successfully installed and used MonetDB in the past as a standalone server, by connecting/querying through "mclient" running on the same machine where server is running. I was trying out web-based access, in which I was trying DBLite's simple web interface http://user.dblite.com (running on the browser on the same machine). My MonetDB server was compiled with "enable-sql", "enable-mserver5", and other optimization options. Not compiled with JDBC/ODBC though (but DBLite is a PHP based interface). "Control" is set to YES and "passphrase" is set to "monetdb" too. While the server is running, I can very well connect and query through command line mclient, but if I give "localhost", port as 50000 and default user/passwd "monetdb/monetdb" on the http://user.dblite.com interface, it keeps giving me "access denied" error. I am wondering what I am missing! Thanks. Medha

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[MonetDB-users] source code structure
by guangliang peng 06 Sep '12

06 Sep '12

hi, i prepare to look at the source code of monnetdb.Can you guys give me some advices which can help reduce the time on the source code .And what's the source code structure? thanks, guangliang

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[MonetDB-users] costmodel
by guangliang peng 06 Sep '12

06 Sep '12

hello, how do i show costmodel where i run a query ?because i want to know the internal execution of a query . thanks, guangliang

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[MonetDB-users] monetdb join path
by guangliang peng 05 Sep '12

05 Sep '12

I now still feel confused about join_path .I have tried the trace ,but the results show many lines with MAL language.It is very hard for me to find out the join path and order.can anyone help me?

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[MonetDB-users] Is there IF(), IFNULL() in SELECT?
by Dmitry Insta 31 Aug '12

31 Aug '12

Sorry if it was asked before, I can't find a comprehensive list of functions available. Is it possible to somehow implement something like this: SELECT IF(col1>0,'Negative','Positive') as Sign, IFNULL(col2,'Empty',col2) as col2 FROM table; // it's just an example, not the exact query :) Thanx!

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[MonetDB-users] how to set see mserver5 config
by guangliang peng 31 Aug '12

31 Aug '12

hi, I want to see mserver5 configure for example dbfarm,dbname. I don't know the command and hwo i set the gdk-vmtrim =no .I don't know hwo to set the GDK PARAMETERS .Can you guys help me? best reguards, guangliang

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[MonetDB-users] Migration DW to MonetDB
by R＠quel 28 Aug '12

28 Aug '12

Hi, I have a question, i need comparison the execution query times between MonetDB and SQL 2008 in Data Warehouse (applying a different orientations database systems). But i have a problem, i used the AdventureWorkR2 2008 but i don't know how i can migrate the information to MonetDB. To compare the same data. Someone help me? Please. It's very important. Thanks, Raquel -- View this message in context: http://old.nabble.com/Migration-DW-to-MonetDB-tp34348184p34348184.html Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] what's the trigger of monetdb releasing memory
by guangliang peng 27 Aug '12

27 Aug '12

hi , when I ran some queries on monetdb,I found that the memory was automatically released by monetdb.And it needs extra time to load data into memory again.I don't know why and if there are some triggers in monetdb? Thank you for helps. best reguards, guangliang

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[MonetDB-users] New Grouping Implementation
by David893 26 Aug '12

26 Aug '12

Hi Folks, I've seen that you re-implemented the grouping functions. Will it have effect on performance (on non-ordered columns)? Right now we're running MonetDB on a 1billion data set, mostly for grouping and aggregating, we're very happy with the performance, but of-course, any improvement is highly welcome :). If it does affect performance, we'll be the first to test and report. you guys rock!, keep up the great work. -- View this message in context: http://old.nabble.com/New-Grouping-Implementation-tp34348175p34348175.html Sent from the monetdb-users mailing list archive at Nabble.com.

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