Re: [MonetDB-users] Embedded Server in Python on Windows XP

13 May 2007


      Thanks for the detailed explanation.
I've logged the request on Sourceforge:
http://sourceforge.net/tracker/index.php?func=detail&aid=1718038&gro...
Cheers.
On 5/12/07, Niels Nes Niels.Nes@cwi.nl wrote:
...
On Sat, May 12, 2007 at 03:52:33PM -0700, Blackie Hlasek wrote:
Hi Blackie,
The embedded version indeed uses a thread for the server and this runs
indeed in the same adress space. The client and server threads communicate
using named pipes.
It should be possible to use the same python module MonetSQLdb.
This module depends on 2 c modules, the MapiLib and monetdb.
The first should be includeded automatically. That should give
you the possiblility to play with monetdb/sql in the reall
client server version.
The later adds the embedded version.
And then you could use
        connect(dbfarm = "location of the dbfarm", dbname = "database
name");
The problem is that the monetdb python module wasn't included in
the installer. The usual solutions for this exist, compile your own
version on windows, change plantform (linux is our main platform), or
ask us for a windows version which includes this module
(the later will atleast take until monday amsterdam time).
Niels
...
Hi Fabian,
   Thank you for your quick reply.
   I understand that MonetDB always run in a client/server model.  I
   guess what I'm looking for is the ability to run it in the same
   address space as the client application written in Python on Win XP.
   For instance, this page:
   [1]http://monetdb.cwi.nl/projects/monetdb/SQL/Documentation/A-Simple
   -Example.html
   gives an example of how it's done in C.  In the 2nd paragraph, it
   stays that "...Upon success of this call, there will be a separate
   server thread running in the same user space to handle the database
   requests."
   I'm trying to figure out how to do the same in Python but there
   doesn't seem to be much documentation.  From what you're saying, I
   guess it's not possible to do it in Python and/or on Windows at the
   moment?  Could you please clarify?  That is: a) can't on Python, b)
   can't on Windows, or c) can't on both?
   Also, I've had a chance to take a glance at the python code and I
   saw the following strange bit in CMapi.py:
   class Embedded(Mapi):
        def __init__(self, dbfarm = None, dbname = "demo", lang =
   "sql"):
      try:
         import monetdb
         if lang == "sql":
               self._Mapi__mid = monetdb.monetdb_sql(dbfarm, dbname)
      except:
               e, value
          print(e)
           if not self._Mapi__mid:
               raise IOError("Creating connection structure failed")
           if self.error():
               raise IOError(self.error_str())
   The following errors are pretty obvious:

Indentation is incorrect, which means that the python crashed

when it reached this section.  It seems strange that while the the
   rest of the file uses spaces for indentation, this particular uses
   tabs.
   2) The "except" clause has incorrect syntax.
   3) There doesn't seem to be a monetdb module to import.
   I've tried to correct it on my own.  I think it probably should look
   something like this (please correct if I'm wrong):
   class Embedded(Mapi):
        def __init__(self, dbfarm = None, dbname = "demo", lang =
   "sql"):
         try:
            import monetdb
            if lang == "sql":
               self._Mapi__mid = monetdb.monetdb_sql(dbfarm, dbname)
         except Exception, value:
            print(value)
            if not self._Mapi__mid:
                raise IOError("Creating connection structure failed")
            if self.error():
                raise IOError(self.error_str())
   But still, not having the monetdb module makes it a no-go....
   On 5/12/07, Fabian Groffen <[2]Fabian.Groffen@cwi.nl > wrote:
       Hi Blackie,
       On 12-05-2007 04:40:41 -0700, Blackie Hlasek wrote:
       >    Just to clarify my last message: I would like to know how
   to use
        >    Python 2.5 (on Win XP) to run monetdb as an embedded
   server.
       MonetDB always runs in a client/server model.  No true embedded
   version
       of MonetDB currently exists.  A slimmed down version of MonetDB
   is as
       far as I am aware not available on the Windows platform.
       >    On 5/12/07, Blackie Hlasek <[1]blck.hl@[3]gmail.com> wrote:
       >
       >      I'm running Python 2.5 on Windows XP Pro SP2.
       >
        >       I've  successfully  installed  the windows binary
   distribution
       >      (MonetDB5-SQL-2.16.2.msi).
       >
       >      I've successfully run the Python example (on the website)
   which
       >      connects to the standalone server.
       >
       >      How do I run monetdb as an embedded server?  Any advice
   would be
       >      appreciated.
       >
       >      Thanks!


   This SF.net email is sponsored by DB2 Express
   Download DB2 Express C - the FREE version of DB2 express and

take
       control of your XML. No limits. Just data. Click to get it now.
       [4]http://sourceforge.net/powerbar/db2/
       _______________________________________________
       MonetDB-users mailing list
       [5]MonetDB-users@lists.sourceforge.net
       [6]https://lists.sourceforge.net/lists/listinfo/monetdb-users
On 5/12/07, Fabian Groffen <[7]Fabian.Groffen@cwi.nl> wrote:
 Hi Blackie,
 On 12-05-2007 04:40:41 -0700, Blackie Hlasek wrote:
 >    Just to clarify my last message: I would like to know how to
 use
 >    Python 2.5 (on Win XP) to run monetdb as an embedded server.
 MonetDB always runs in a client/server model.  No true embedded
 version
 of MonetDB currently exists.  A slimmed down version of MonetDB is
 as
 far as I am aware not available on the Windows platform.
 >    On 5/12/07, Blackie Hlasek <[1]blck.hl@ [8]gmail.com> wrote:
 >
 >      I'm running Python 2.5 on Windows XP Pro SP2.
 >
 >      I've successfully installed the windows binary distribution
 >      ( MonetDB5-SQL-2.16.2.msi).
 >
 >      I've successfully run the Python example (on the website)
 which
 >      connects to the standalone server.
 >
 >      How do I run monetdb as an embedded server?  Any advice
 would be
 >      appreciated.
 >
 >      Thanks!
 ------------------------------------------------------------------
 -------
 This SF.net email is sponsored by DB2 Express
 Download DB2 Express C - the FREE version of DB2 express and take
 control of your XML. No limits. Just data. Click to get it now.
 [9]http://sourceforge.net/powerbar/db2/
 _______________________________________________
 MonetDB-users mailing list
 [10]MonetDB-users@lists.sourceforge.net
 [11]https://lists.sourceforge.net/lists/listinfo/monetdb-users


References


http://monetdb.cwi.nl/projects/monetdb/SQL/Documentation/A-Simple-Example.ht...
...

mailto:Fabian.Groffen@cwi.nl
http://gmail.com/
http://sourceforge.net/powerbar/db2/
mailto:MonetDB-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/monetdb-users
mailto:Fabian.Groffen@cwi.nl
http://gmail.com/
http://sourceforge.net/powerbar/db2/
mailto:MonetDB-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/monetdb-users

...

...
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
MonetDB-users mailing list
MonetDB-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/monetdb-users
--
Niels Nes, Centre for Mathematics and Computer Science (CWI)
Kruislaan 413, 1098 SJ Amsterdam, The Netherlands
room C0.02,  phone ++31 20 592-4098, fax ++31 20 592-4312
url: http://www.cwi.nl/~niels   e-mail: Niels.Nes@cwi.nl