Board index » delphi » Newbie : multiple clients connected to a database

carte...@news.ececs.uc.edu (Richard Carter)

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Newbie : multiple clients connected to a database

Quote
YXENDIS (Armindo.Da-Si...@wanadoo.fr) wrote:

: I have an application that use BDE with a paradox database.
: in this database there are some big pictures stored in a blob.

: for the moment only one user is connected to the database.
: I would like to connect 15 users to this database on a network, but I'm
: afraid that the access become very slow.

I don't know the size of your table and the number of records,
but I should think you can make this work with Paradox tables
and the BDE.

One change you could consider is storing the path to the
graphic as text in your table, rather than storing the complete
graphic (assuming it will be the same path for all users).
--
Rick Carter
carte...@email.uc.edu

 
YXENDI

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Newbie : multiple clients connected to a database


Hi there,

I have an application that use BDE with a paradox database.
in this database there are some big pictures stored in a blob.

for the moment only one user is connected to the database.
I would like to connect 15 users to this database on a network, but I'm
afraid that the access become very slow.

What do you suggest me to do :
  -let it like that.
  -make a dcom server with this paradox database.
  -port it for to an interbase client/serve solution.

For me this decision is very important because it mean that I should by a
new delphi version (probably delphi C/S).

thanks for your help.

Armindo

Armindo.Da-Si...@wanadoo.fr

Markku Nevalaine

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Newbie : multiple clients connected to a database


Quote
YXENDIS wrote:

> What do you suggest me to do :
>   -let it like that.
>   -make a dcom server with this paradox database.
>   -port it for to an interbase client/serve solution.

Try letting it like that. You did not say if those 15 users are
active at the same time, searching and updating the database. Even
in that case, BDE/Paradox has good chances to give reasonable
results.

Of course, if one picture from your BLOB field is 1..2 MB in size,
and everybody should be able to loop through them in sequence, in
some seconds only, then it probably won't work. But the bottleneck
could as well be 10 Mbit/s ethernet adapter, or the servers hard
disk I/O.
Yet, a C/S database won't eliminate this kind of problems, Paradox
maybe is even faster in here.

Quote
> For me this decision is very important because it mean that I should by a
> new delphi version (probably delphi C/S).

It depends on the database. You don't need a C/S version of Delphi
to use some of those third party C/S databases, FlashFiler, Advantage
etc.

You better try to install your app somewhere where you can test
it with those 15 users, and see what happens.

There are also several commercial technicues to handle, search
and retrieve large set of pictures from database. Sorry, I'm not
a specialist on this arena.

Markku Nevalainen

YXENDI

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Newbie : multiple clients connected to a database


Hi

Quote
>Try letting it like that. You did not say if those 15 users are
>active at the same time, searching and updating the database. Even
>in that case, BDE/Paradox has good chances to give reasonable
>results.

yes it is 15 users at the same time....

Quote
>Of course, if one picture from your BLOB field is 1..2 MB in size,
>and everybody should be able to loop through them in sequence, in
>some seconds only, then it probably won't work. But the bottleneck
>could as well be 10 Mbit/s ethernet adapter, or the servers hard
>disk I/O.
>Yet, a C/S database won't eliminate this kind of problems, Paradox
>maybe is even faster in here.

>> For me this decision is very important because it mean that I should by a
>> new delphi version (probably delphi C/S).

>It depends on the database. You don't need a C/S version of Delphi
>to use some of those third party C/S databases, FlashFiler, Advantage
>etc.

Do you know where to download these third party C/S databases?

Quote
>You better try to install your app somewhere where you can test
>it with those 15 users, and see what happens.

For the moment I use DBISAM database.
I think I will port it to paradox.
Do you suggest me to only put the database on a pc and simply access the
datbase or do you suggest me to put it on a dcom server (if it exist).

Do you know if I

thanks for your help.

Armindo.

Markku Nevalaine

Delphi Developer
Wed, 18 Jun 1902 08:00:00 GMT

Re:Newbie : multiple clients connected to a database


Quote
YXENDIS wrote:

> For the moment I use DBISAM database.
> I think I will port it to paradox.

In your first message you told you currently have BDE and Paradox
tables??
The speed difference between BDE/Paradox and DBISAM should be quite
small, DBISAM slightly slower. Those DBISAM guys promise their speed
will soon increase, and also their C/S version should be out during
this year.

Quote
> Do you suggest me to only put the database on a pc and simply access the
> datbase or do you suggest me to put it on a dcom server (if it exist).

I don't know what kind of system you are building. I can quess it could
be something Internet-related, accessing DB files over Internet or?
If it is that, then Paradox is out of the question. As far as I know,
no version of BDE/Paradox knows anything about DCOM, won't work
there etc.

If you are looking relatively cheap and quick DB to work within ethernet
cable (means, no slow lines anywhere), then Paradox and DBISAM are good
choices, even with 15 simultaneous users.

But if you plan to build some internet accessed stuff, you need a true
SQL database. One clear choice could be to start studying how you could
use Microsoft's SQL Server as your database, and Delphi as your development
environment. Sorry, I'm not able to give any detailed answers in here.

Markku Nevalainen

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