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December 2010

14 participants
12 discussions

[MonetDB-users] Some questions regarding parallelism and other stuff...
by Mike De-La-Columnar 06 Dec '10

06 Dec '10

Hi fellas, If its not too much of a hassle, i have a few questions regarding parallelism & the internal algorithms 1. What is the difference between Data-Flow, and Mitosis? 2. Is there a special reason why the distinct count aggregation is not parallelized just like the other aggregation functions? Is it just a matter of not making it into the release, or is there a fundamental problem here. Note: even though the parallel distinct can be slower in certain distributions, it could still be useful... 3. Are there any plans on supporting parallel frameworks like OpenMP/Intel TBB directly within the low-level MAL functions? Providing data-parallelism on the loop-code level could even increase performance. Or did you already play with it and decided that the performance gain is just not worth it? 4. Is there a way for me to prevent MonetDB server from cleaning up all intermediate BATs between server restarts. I've read here that some intermediates (like join indices etc.) are lost between restarts... is it still correct? Thank you very much for your time, Keep up the amazing job of building the most powerful columnar database out there! -- View this message in context: http://old.nabble.com/Some-questions-regarding-parallelism-and-other-stuff.… Sent from the monetdb-users mailing list archive at Nabble.com.

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[MonetDB-users] MonetDB/XQuery Installation
by Rob Fynes 01 Dec '10

01 Dec '10

Hello, Apologies if this is the improper place to be asking this. I'm a new user to MonetDB, and I'm having trouble installing MonetDB/XQuery on Ubuntu 10.04 32-bit. Actually, the installation did seem to succeed (running the auto install script from the super source tarball) and I can start MServer, but with the error: # MonetDB Server v4.40.2 # based on GDK v1.40.2 # not released # Copyright (c) 1993-July 2008, CWI. All rights reserved. # Copyright (c) August 2008-2010, MonetDB B.V.. All rights reserved. # Compiled for i686-pc-linux-gnu/32bit with 32bit OIDs; dynamically linked. # Detected 3.919 GiB (4208013312 bytes) main-memory. # Visit http://monetdb.cwi.nl/ for further information. !ERROR: moduleClient: module(pathfinder) load error. The problem, its seems anyway, is during the configuration of pathfinder: ... ... checking for signal.h... yes checking return type of signal handlers... (cached) void checking for strings.h... (cached) yes checking for strcasecmp... yes checking for xml2-config.32... no checking for xml2-32-config... no checking for xml2-config... no checking for libxml/parser.h... no configure: error: in `/home/rob/MonetDB': configure: error: The libxml2 XML parsing library and/or include files were not found or you have requested to not use it. This is required dependence, core components like the XML Schema import functionality depends on it. See `config.log' for more details. I do have libxml2 installed (by default with Lucid). I've run the pathfinder configure script a few times, with the option --with-libxml2=*some variations*, but I'm not really confident about what I'm doing. I was wondering if anyone could point me in the right direction. Thanks. -Rob

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