Which data engine?

[Leslie Isaacs]

Hello All

Apologies for the cross-posting - but in case I have omitted the most
appropriate group I would be very grateful if someone could direct me to
whichever it might be.

I am contemplating the development of a General Management application for
use in doctors' surgeries. The application will be wide-ranging, including
modules for payroll, accounts, rotas, significant event reporting and
analysis, personnel, plus others.

I need to decide between using MSDE or the full SQL Server engine. For
obvious cost reasons MSDE would be preferable, but despite having read all I
can find on the web I am still unsure about the concurrent user limitations
of MSDE. Does anyone out there have experience of having deployed an
application using MSDE into an environment in which there are regularly,
say, 10 concurrent users? Or 20? Does MSDE allow for 'queuing' of loggins,
after a given threshold?

I would be very grateful to hear from anyone with experience of these
issues, or for any pointers to where I might find people with this
experience.

Many thanks.
Leslie Isaacs

 

[Sylvain Lafontaine]

MSDE is tuned for five concurrent connections, but a connection is not the
same thing as a login. You can have tens of logins and still have a
handfull of connections.

Also, you don't have to decide beetween MSDE or SQL-Server. Excerpt for
very fews and specialised functions, MSDE offer the same support as
SQL-Server, with the only exception behing the maximum size of the database.
However, if you want to switch later from MSDE to SQL-Server, it's a very
easy step and involve no change in your coding.

My suggestion for you would be to buy the Developer Edition of SQL-Server,
at about 50$US, and start learning the stuff.

S. L.

 

[Steve Jorgensen]

I believe the number of connections is no loger how the MSDE does its
throttling. Instead, it's the number of concurrent requests (probably since
zombie connections are such a ubiquitous issue). This means that, once 5
concurrent requests are already being processed, any additional requests wait
in a Queue until one of the original 5 is completed.

In any case, if you hover around the 10 user mark, and the users are doing
mostly data entry and single-record lookups, with a few reports and analyses
here and there, you're doing fine (so long as the 2GB database size limit is
also adequate). Much beyond that, and users will start to complain, and you
may experience timeout errors.

 

[Leslie Isaacs]

Thanks for your replies.

Now my question also involves MySQL - where does that fit in with MSDE and
SQLServer?

This get more complex the more I look into it!

Is there anyone out there who can give me, in just a few lines or
paragraphs, the significant differences between MSDE, MySQL & full-blown
SQLServer - apart from the concurent useage issues with MSDE that are
well-documented.

Hope someone can help.
Les

 

[david epsom dot com dot au]

And SQL Express Edition (which last I looked was a free download!)
removes 'artificial' limits entirely (although it is still has build
limitations which make it more suitable for small numbers of users
on small servers).

MSDE 2000 doesn't just queue requests - it inserts delay when
you have more than 8 operations running:
http://msdn.microsoft.com/library/en-us/architec/8_ar_sa2_0ciq.asp

I believe that the previous version of MSDE queued requests:
I don't think any version limited connections (I think that
was just a misunderstanding of the request queue)

(david)

 

[brigitte olier]

And SQL Express Edition (which last I looked was a free download!)
removes 'artificial' limits entirely (although it is still has build
limitations which make it more suitable for small numbers of users
on small servers).

MSDE 2000 doesn't just queue requests - it inserts delay when
you have more than 8 operations running:
http://msdn.microsoft.com/library/en-us/architec/8_ar_sa2_0ciq.asp

I believe that the previous version of MSDE queued requests:
I don't think any version limited connections (I think that
was just a misunderstanding of the request queue)

(david)