Hello guys,
I aplogize for bothering you with what might be a simple issue for you, but I am new to monetDB and I have to solve some complex problems for which I cannot find a solution by myself. I've read about MAL in the M5 reference manual. I recognized, the normal way to execute commands is via MAPI and JDBC and stuff based on MAPI. This will be parsed into MAL, optimized and executed. Is there a way to write MAL code and give it as input to the server directly??
Another question: Is it possible to explicitely invoke execution of a query in multiple threads via MAPI or other means?
Kind regards, michael
Le Wednesday 02 Feb 2011 à 11:56:00 (+0100), Michael Kusber a écrit :
Hello guys,
I aplogize for bothering you with what might be a simple issue for you, but I am new to monetDB and I have to solve some complex problems for which I cannot find a solution by myself. I've read about MAL in the M5 reference manual. I recognized, the normal way to execute commands is via MAPI and JDBC and stuff based on MAPI. This will be parsed into MAL, optimized and executed. Is there a way to write MAL code and give it as input to the server directly??
Yes, I'm not sure that there is a client that allows to do so, but using the MAPI C interface, you can definitely feed MAL code.
Another question: Is it possible to explicitely invoke execution of a query in multiple threads via MAPI or other means?
To my knowledge, a client is attached to a single thread. Now MonetDB may do stuff under the hood, but I'm not so sure about how you could control that.
Surely someone else will give you a more detailed answer.
Kind regards,
michael
On Wed, Feb 2, 2011 at 4:56 AM, Michael Kusber < michael.kusber@googlemail.com> wrote:
Hello guys,
I aplogize for bothering you with what might be a simple issue for you, but I am new to monetDB and I have to solve some complex problems for which I cannot find a solution by myself. I've read about MAL in the M5 reference manual. I recognized, the normal way to execute commands is via MAPI and JDBC and stuff based on MAPI. This will be parsed into MAL, optimized and executed. Is there a way to write MAL code and give it as input to the server directly??
It's been a while but if memory serves, I think you can start from the
example c mapi client and in the connect call simply pass "mal" for the language parameter instead of "sql", and start experimenting. I don't think you can do the same via JDBC however.
http://monetdb.cwi.nl/MonetDB/Documentation/An-Example.html#An-Example
Not sure if this is your question, but the 'pipeline' you're running with determines how monet will handle the query internally. See monetdb5.conf to select the pipeline. The default pipeline should include pipes, like mitosis, that split a query in chunks, each one of which can be executed be a separate thread. However you don't have any control over this (nor should you).
Another question: Is it possible to explicitely invoke execution of a query in multiple threads via MAPI or other means?
Not sure if this is your question, but the 'pipeline' you're running with determines how monet will handle the query internally. See monetdb5.conf to select the pipeline. The default pipeline should include pipes, like mitosis, that split a query in chunks, each one of which can be executed be a separate thread. However you don't have any control over this (nor should you).
Jason
participants (3)
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Guillaume Yziquel -
Jason Kinzer -
Michael Kusber