Yes , after I add gdk_nr_threads=2 to the config file, the mserver.exe says 2 threads are used, but it seems there are some problems:
When I use SQuirrel SQL Client  connect to my new database, the mserver.exe process' CPU usage is very high(98%) whenever a statement is sent to the server. the following sample stataments even runs for a second.
create table t1 ( a int not null, b varchar(1024) );
create table t2 ( a int not null, c varchar(1024));
 
insert into t1 values(1, 'b1');
insert into t1 values(2, 'b2');
insert into t1 values(3, 'b3');
 
insert into t1 values(1, 'c1');
insert into t1 values(2, 'c2');
 
select t1.* ,t2.c from t1 left outer join t2 on t1.a = t2.a

There is also an error message like " memory heap courput" which I can't re produce.
 
 

> Date: Fri, 2 Jan 2009 09:44:32 +0100
> From: Stefan.Manegold@cwi.nl
> To: monetdb-users@lists.sourceforge.net
> Subject: Re: [MonetDB-users] Monetdb5 threading question.
>
> On Fri, Jan 02, 2009 at 04:28:31PM +0800, 小波 顾 wrote:
> >
> > When I start the default demo database (or a new created one) process on Windows XP, the following messaged appears in the command window :
> > # Serving databse 'demo', using 1 thread
> >
> > Does it mean the whole database process is single-threaded?
> > The following section in the monetdb5.config file shows we can config multiple threads
> >
> > # Mserver 5 recognizes a series of command line names instead:# --threads ( 1 | PARMASK)# --memory (MEMMASK )# --properties (CHECKMASK | PROPMASK | BATMASK )# --io (IOMASK | PERFMASK )# --transactions ( TMMASK | DELTAMASK | TEMMASK)# --modules (DLMASK | LOADMASK)# --algorithms (ALGOMASK | ESTIMASK)# --xproperties (XPROPMASK )# --performance (JOINPROPMASK | DEADBEEFMASK)
> >
> > What does 'parmsk' mean, and how to config monetdb to use multiple threads?
>
> If you read the whole monetdb5.conf file, you'll find
>
> ========
> [...]
> # You can enable debug for specific parts. By default debug is
> # switched off.
> gdk_debug=0
> # possible values: (can be a combination of)
> # 1 = thread-specific debug output
> # 2 = CHECKMASK = property enforcing on new BATs
> # 4 = MEMMASK = memory allocation
> # 8 = PROPMASK = property checking on all values: tells about
> # wrongly set properties
> # 16 = IOMASK = major IO activity
> # 32 = BATMASK = BAT handling
> # 64 = PARSEMASK = parser debugging
> # 128 = PARMASK = Thread management
> ^^^ ^^^^^^^ ^^^^^^^^^^^^^^^^^
> # 256 = TRGMASK = Event management
> # 512 = TMMASK = Transaction management
> # 1024 = TEMMASK = Locks and Triggers
> # 2048 = DLMASK = Dynamic loading
> # 4096 = PERFMASK = BBP Performance (?)
> # 8192 = DELTAMASK = Delta debugging (?)
> # 16384 = LOADMASK = Module loading
> # 32768 = YACCMASK = Yacc specific error messages
> # 65536 = obsolete = tcpip (??)
> # 131072 = obsolete = monet_multiplex: setaggr debugging (??)
> # 262144 = obsolete = \
> # 524288 = obsolete = ddbench (???)
> # 1048576 = obsolete = /
> # 2097152 = ALGOMASK = show join/select algorithm chosen
> # 4194304 = ESTIMASK = show result size estimations (for join,select)
> # 8388608 = XPROPMASK = extended property checking: tells also about
> # not set properties
> #16777216 = JOINPROPMASK = disable property checking with join & outerjoin
> # (e.g., for performance measurements)
> #33554432 = DEADBEEFMASK = disable "cleaning" of freed memory in GDKfree()
> # (e.g., for performance measurements)
> #
> # Mserver 5 recognizes a series of command line names instead:
> # --threads ( 1 | PARMASK)
> # --memory (MEMMASK )
> # --properties (CHECKMASK | PROPMASK | BATMASK )
> # --io (IOMASK | PERFMASK )
> # --transactions ( TMMASK | DELTAMASK | TEMMASK)
> # --modules (DLMASK | LOADMASK)
> # --algorithms (ALGOMASK | ESTIMASK)
> # --xproperties (XPROPMASK )
> # --performance (JOINPROPMASK | DEADBEEFMASK)
> [...]
> ========
>
> Hence, the '--thread' option is "just" to get debug output about multi threading.
>
> MonetDB runs multi-threaded, but by default only uses one thread per
> client/query (multiple clients are served concurrently); to get parallel
> processing of a single query (makes sense only on multi-core SMP machines)
> you can set the number of threads on the mserver5 command line via
>
> `mserver5 --set gdk_nr_threads=<nr-threads> ...`
>
> or in the monetdb5.conf file via
>
> 'gdk_nr_threads=<nr-threads>'
>
>
> Stefan
>
> > _________________________________________________________________
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> > http://www.microsoft.com/windows/windowslive/
> > ------------------------------------------------------------------------------
>
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> > MonetDB-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/monetdb-users
>
>
> --
> | Dr. Stefan Manegold | mailto:Stefan.Manegold@cwi.nl |
> | CWI, P.O.Box 94079 | http://www.cwi.nl/~manegold/ |
> | 1090 GB Amsterdam | Tel.: +31 (20) 592-4212 |
> | The Netherlands | Fax : +31 (20) 592-4312 |
>
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