Thread: OLE DB driver

OLE DB driver

From
Shachar Shemesh
Date:
Hi all,

After unsuccessfully trying to join the current OLE DB project on gborg, 
I'm writing my own. So far I don't have anything too fancy (just trying 
to get over the initial shock of what OLE DB actually is). It currently 
does the basic infrastructure, but does not yet actually connect to 
Postgresql. If anyone else has written code, was contemplating writing 
code, has access to the gborg project, or is otherwise interested, 
please let me know.

I'm hoping to be able to do some sort of preliminary release in about a 
week.
            Shachar

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/




Re: OLE DB driver

From
Andreas Pflug
Date:
Shachar Shemesh wrote:

> Hi all,
>
> After unsuccessfully trying to join the current OLE DB project on 
> gborg, I'm writing my own. So far I don't have anything too fancy 
> (just trying to get over the initial shock of what OLE DB actually 
> is). It currently does the basic infrastructure, but does not yet 
> actually connect to Postgresql. If anyone else has written code, was 
> contemplating writing code, has access to the gborg project, or is 
> otherwise interested, please let me know.
>

I wonder if this could be implemented as a wrapper around libpq. This 
way, the OLEDB driver would benefit from a proven piece of software.

Regards,
Andreas




Re: OLE DB driver

From
Shachar Shemesh
Date:
Andreas Pflug wrote:

> I wonder if this could be implemented as a wrapper around libpq. This 
> way, the OLEDB driver would benefit from a proven piece of software.
>
> Regards,
> Andreas

That's what I'm doing. I'm not sure why other drivers didn't do that as 
well (maybe there was no native Windows port of libpq at the time?).

My reason is actually that I'm not a great postgres hacker, and I would 
rather rely as little as possible on internal structures and things that 
are likely to change in the future.
               Shachar

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/




Re: OLE DB driver

From
Andreas Pflug
Date:
Shachar Shemesh wrote:

> Andreas Pflug wrote:
>
>> I wonder if this could be implemented as a wrapper around libpq. This 
>> way, the OLEDB driver would benefit from a proven piece of software.
>>
>> Regards,
>> Andreas
>
>
> That's what I'm doing. I'm not sure why other drivers didn't do that 
> as well (maybe there was no native Windows port of libpq at the time?).
>
> My reason is actually that I'm not a great postgres hacker, and I 
> would rather rely as little as possible on internal structures and 
> things that are likely to change in the future.


Sounds good. While I probably won't find time helping implementing the 
driver; I have an OLEDB app running that currently uses 
MSDASQL/psqlODBC. I'd certainly like testing your driver, and give 
feedback from that. When do you expect first usable versions?

Regards,
Andreas




Re: OLE DB driver

From
Shachar Shemesh
Date:
Andreas Pflug wrote:

> Sounds good. While I probably won't find time helping implementing the 
> driver; I have an OLEDB app running that currently uses 
> MSDASQL/psqlODBC. I'd certainly like testing your driver, and give 
> feedback from that.

That would be great.

> When do you expect first usable versions?

That depends. I'm hoping to have a version that implements the basic 
(read - mandatory) interfaces later this week. A more broad version will 
take longer.

I also wanted to ask the list's opinion about a gborg/sourceforge 
hosting. The current oledb project on gborg seems dead. Should I open 
another one?
            Shachar

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/




Re: OLE DB driver

From
"William ZHANG"
Date:
"Shachar Shemesh" <psql@shemesh.biz> wrote:3FFF1607.9090806@shemesh.biz...
> Andreas Pflug wrote:
>
> > I wonder if this could be implemented as a wrapper around libpq. This
> > way, the OLEDB driver would benefit from a proven piece of software.
> >
> > Regards,
> > Andreas
>
> That's what I'm doing. I'm not sure why other drivers didn't do that as
> well (maybe there was no native Windows port of libpq at the time?).

AFAIK, rely on libpq is a fast way but not always convenient.
OLEDB has many features borrowed from ODBC, and it is a
substitute for ODBC. Microsoft is now making ODBC obsolete and
advocating OLEDB instead. You'd better read pgodbc's source
code, too.

>
> My reason is actually that I'm not a great postgres hacker, and I would
> rather rely as little as possible on internal structures and things that
> are likely to change in the future.
>
>                 Shachar
>
> --
> Shachar Shemesh
> Lingnu Open Systems Consulting
> http://www.lingnu.com/
>
>
>
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>




Re: OLE DB driver

From
Shachar Shemesh
Date:
William ZHANG wrote:

>"Shachar Shemesh" <psql@shemesh.biz> wrote:3FFF1607.9090806@shemesh.biz...
>  
>
>>Andreas Pflug wrote:
>>
>>    
>>
>>>I wonder if this could be implemented as a wrapper around libpq. This
>>>way, the OLEDB driver would benefit from a proven piece of software.
>>>
>>>Regards,
>>>Andreas
>>>      
>>>
>>That's what I'm doing. I'm not sure why other drivers didn't do that as
>>well (maybe there was no native Windows port of libpq at the time?).
>>    
>>
>
>AFAIK, rely on libpq is a fast way but not always convenient.
>  
>
Seems like more convinent than hacking the client/server protocol 
myself. I may come up to a wall later on, and then I may reconsider.

>OLEDB has many features borrowed from ODBC, and it is a
>substitute for ODBC. Microsoft is now making ODBC obsolete and
>advocating OLEDB instead. You'd better read pgodbc's source
>code, too.
>
>  
>
I did some of that, and did some ODBC hacking too (very little). The 
fact that ODBC uses it's own protocol implementation, I think, is a 
mistake. There are places where some intervention is going to be 
unavoidable, I'm afraid, but that has nothing to do with what protocol 
to use for communicating with the back end. If Postgres doesn't support 
writeable cursors, then it doesn't support writeable cursors. One has to 
emulate them. I will defenitely use some borrowing from pgsqlODBC (the 
main reason my OLE DB is LGPL was so I can do that).

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/




Re: OLE DB driver

From
Robert Treat
Date:
On Saturday 10 January 2004 13:55, Shachar Shemesh wrote:
> Andreas Pflug wrote:
> > Sounds good. While I probably won't find time helping implementing the
> > driver; I have an OLEDB app running that currently uses
> > MSDASQL/psqlODBC. I'd certainly like testing your driver, and give
> > feedback from that.
>
> That would be great.
>
> > When do you expect first usable versions?
>
> That depends. I'm hoping to have a version that implements the basic
> (read - mandatory) interfaces later this week. A more broad version will
> take longer.
>
> I also wanted to ask the list's opinion about a gborg/sourceforge
> hosting. The current oledb project on gborg seems dead. Should I open
> another one?
>

Can you fill us in on your efforts to contact the original project author?  If 
those efforts have failed and the code is no longer being maintained, we can 
contact the gborg maintainer about making you the admin for the project. I 
don't think there is an official policy on this, but this seems like a 
reasonable request as long as your willing to either update the old code or 
leave it as it's own seperate module within the cvs tree.

Robert Treat
-- 
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL


Re: OLE DB driver

From
"Dave Page"
Date:

> -----Original Message-----
> From: Shachar Shemesh [mailto:psql@shemesh.biz]
> Sent: 11 January 2004 20:21
> To: William ZHANG
> Cc: pgsql-hackers@postgresql.org
> Subject: Re: [HACKERS] OLE DB driver
>
> >AFAIK, rely on libpq is a fast way but not always convenient.
> >
> >
> Seems like more convinent than hacking the client/server
> protocol myself. I may come up to a wall later on, and then I
> may reconsider.

Seems unlikely - libpq is the definitive implementation of the protocol.


> >
> I did some of that, and did some ODBC hacking too (very
> little). The fact that ODBC uses it's own protocol
> implementation, I think, is a mistake.

Yes, it would be easier if that were not the case - unfortunately that
decision was made many years ago -
http://pluto.iis.nsk.su/postgres95/postgres95.ODBC/

Regards, Dave.


Re: OLE DB driver

From
Shachar Shemesh
Date:
Robert Treat wrote:

>Can you fill us in on your efforts to contact the original project author?
>
Sure thing. Here it is:
The project is located at 
http://gborg.postgresql.org/project/oledb/projdisplay.php. It has 
released no code, shows no CVS activity, and seems rather empty. There 
are two tasks listed, without any status attached to them. There was one 
bug, which suggests that there used to be some code, but it's in 
"submitted" state, and I'm not sure what it relates to.

The front page says "please email me if you want to join". However, I 
could not locate the email address for "mosiu", the administrator. 
Lastly, I used the form to ask to become a developer of this project 
(about a month ago). I have received no answer of any kind. As such, I 
reached the conclusion that this project is terminally dead, and that 
it's code is unrecoverable.

>  If 
>those efforts have failed and the code is no longer being maintained, we can 
>contact the gborg maintainer about making you the admin for the project.
>
I would love it if you contacted him, but I don't even have the code for 
the current project. The bug report seems to suggest that such a code 
exists, but I'm damned if I can find it.

> I 
>don't think there is an official policy on this, but this seems like a 
>reasonable request as long as your willing to either update the old code or 
>leave it as it's own seperate module within the cvs tree.
>  
>
Like I said, there doesn't appear to be any old code to maintain. I have 
requested a new project on gborg (pgoledb), but getting the current name 
is just as good. If the current code is somehow recovered, I'll be more 
than glad to have a look at it. After all - I don't INSIST on writing 
from scratch.

>Robert Treat
>  
>            Shachar

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/




Re: OLE DB driver

From
Robert Treat
Date:
Chris,

do you have any additional info (email?) on how to contact the original 
project admin?  Is it possible for you to manually set up Shachar as admin on 
the project?  

Robert Treat

On Monday 12 January 2004 04:30, Shachar Shemesh wrote:
> Robert Treat wrote:
> >Can you fill us in on your efforts to contact the original project author?
>
> Sure thing. Here it is:
> The project is located at
> http://gborg.postgresql.org/project/oledb/projdisplay.php. It has
> released no code, shows no CVS activity, and seems rather empty. There
> are two tasks listed, without any status attached to them. There was one
> bug, which suggests that there used to be some code, but it's in
> "submitted" state, and I'm not sure what it relates to.
>
> The front page says "please email me if you want to join". However, I
> could not locate the email address for "mosiu", the administrator.
> Lastly, I used the form to ask to become a developer of this project
> (about a month ago). I have received no answer of any kind. As such, I
> reached the conclusion that this project is terminally dead, and that
> it's code is unrecoverable.
>
> >  If
> >those efforts have failed and the code is no longer being maintained, we
> > can contact the gborg maintainer about making you the admin for the
> > project.
>
> I would love it if you contacted him, but I don't even have the code for
> the current project. The bug report seems to suggest that such a code
> exists, but I'm damned if I can find it.
>
> > I
> >don't think there is an official policy on this, but this seems like a
> >reasonable request as long as your willing to either update the old code
> > or leave it as it's own seperate module within the cvs tree.
>
> Like I said, there doesn't appear to be any old code to maintain. I have
> requested a new project on gborg (pgoledb), but getting the current name
> is just as good. If the current code is somehow recovered, I'll be more
> than glad to have a look at it. After all - I don't INSIST on writing
> from scratch.
>
> >Robert Treat
>
>              Shachar

-- 
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL