abou different performaces between SQL and MAL

Stephen P. Morgan stephen_p_morgan at sbcglobal.net
Wed Jul 3 19:18:21 CEST 2013


I noticed the same thing for this query in this environment.  There appears to be a 15 second delay in producing the results after sql.exportResults has been called in the MAL version of the code.  I tried using valgrind (callgrind) to determine where the extra cycles were being used, but found that there weren't really any.  That is, the SQL and MAL code were running in about the same number of cycles (give or take 1.8%) and the distributions to the various components were very close to the same for the two cases.  It's as if nothing is going on during the final 15 seconds or so of the MAL query.  I couldn't explain the discrepancy.

Steve



>________________________________
> From: Yanchen <kkuse20 at yahoo.com>
>To: "developers-list at monetdb.org" <developers-list at monetdb.org> 
>Sent: Tuesday, July 2, 2013 11:18 AM
>Subject: abou different performaces between SQL and MAL
> 
>
>
>Hi,
>
>
>May I have a question about MonetDB performance on TPC-H benchmark?
>
>
>I do not know why I got very different performances when I run 01.sql in TPC-H and the explained 01.mal in mal domain. The average execution time for sql against SF100 scale factor is 19.94s, and the time for mal is 34.7. I also tried to use stethoscope to see the detail, seems like mal stop for several seconds before the last line code. Please let me know if you have any thoughts about that. Thank you so much in advance. 
>
>
>
>Best,
>Lou
>
>
>
>
>
>
>
>I am using Monetdb 11.15.3(Feb. 2013). My mserver5 information is as followed:
>
>
>MonetDB 5 server v11.15.3 "Feb2013-SP1" (64-bit, 64-bit oids)
>Copyright (c) 1993-July 2008 CWI
>Copyright (c) August 2008-2013 MonetDB B.V., all rights reserved
>Visit http://www.monetdb.org/ for further information
>Found 188.9GiB available memory, 32 available cpu cores
>Libraries:
>  libpcre: 8.30 2012-02-04 (compiled with 8.30)
>  openssl: OpenSSL 1.0.1c 10 May 2012 (compiled with OpenSSL 1.0.1c 10 May 2012)
>  libxml2: 2.8.0 (compiled with 2.8.0)
>Compiled by: root at LLL-MMMDB2 (x86_64-unknown-linux-gnu)
>Compilation: gcc  -g  -Werror -Wall -Wextra -W -Werror-implicit-function- declaration -Wpointer-arith -Wdeclaration-after-statement -Wundef -Wformat=2 
-Wno-format-nonliteral -Winit-self -Winvalid-pch -Wmissing-declarations 
-Wmissing-format-attribute -Wmissing-prototypes -Wold-style-definition -Wpacked -Wunknown-pragmas 
-Wvariadic-macros -fstack-protector-all -Wstack-protector 
-Wpacked-bitfield-compat -Wsync-nand -Wjump-misses-init 
-Wmissing-include-dirs -Wlogical-op -Wunreachable-code
Linking    : /usr/bin/ld -m elf_x86_64
>
>
>
>
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