Re: Oracle & Delphi

Well, it's not actually that bad for the server if you open more connections. Indeed, if server runs in dedicated mode, new process (or thread on Windows) is started to service your connection and a lot of such processes may well deplete your server RAM. In MTS mode, actual number of processes is fixed and they are shared among all connections.

One connection per application means you have to serialize all database access through this single connection. If you open parallel connections to the database as needed, you can do things concurrently (for example, fetch in background or run separate transactions in separate windows of your application.) Oracle is highly concurrent database and can handle a lot of concurrent connections with ease and without certain issues plaguing other databases, like locking everything they touch and blocking everyone who wants the data you're modifying or wants to modify the data you're reading.

I think your reference to 15 connections is what you entered into DBCA input box for estimated number of concurrent users when you created the database. DBCA just sized certain Oracle parameters accordingly to avoid resource wastage, but of course Oracle can handle more connections than that even with this default sizing, and you can always increase some parameters according to actual load and resource shortages. If server memory is of issue and your transactions are mostly short, then MTS is likely for you, otherwise don't worry about your apps opening a lot of connections, Oracle can easily handle them.

Corrections and additions welcome.

--
Vladimir Zakharychev (bob@dpsp-yes.com)                http://www.dpsp-yes.com
Dynamic PSP(tm) - the first true RAD toolkit for Oracle-based internet applications.
All opinions are mine and do not necessarily go in line with those of my employer.


"Laurent Boutet" <laurent.boutet_at_clinsight.fr> wrote in message
news:al5883$ha4$1_at_reader1.imaginet.fr...


> well...sorry...i hardly explained myself...

> Oracle used is 8.1.7.0.0

>

> I'm connecting with Delphi components called DOA with TOracleSession, just

> like a TDataBase...

>

> About the 15 connection, I may not have understood what Oracle said...when I

> created my Oracle Database,

> it just asked me the number of simultaneous connections...and indeed, it is

> not the max user connections...sorry...but I wanted to understand if it was

> "bad" for the database to have a lot of connections. One connection is best

> than two ?? It slows down the server, doesn t it ???

>

> Thanks in advance

>

> "Daniel Morgan" <dmorgan_at_exesolutions.com> a écrit dans le message de news:

> 3D7621B7.64603FA6_at_exesolutions.com...

> > Laurent Boutet wrote:

> >

> > > Hi !

> > > I've got few questions...

> > > These questions may be stupid, but I'm not a DBA, and I'm hungry to

 learn


> > > ;-)...

> > >

> > > So, I've got a big project,almost 8 programs which depend on each

 other...,


> > > developped with Delphi.

> > > And I was juste wondering a stupid question...all my programs have

> > > connections to my Oracle Server.

> > > If I remember, I can configure my Oracle database to allow a max user

> > > connections (default 15). And then, what is going on after 15

 connections


> > > ???

> > > What is the aim of this configuration ??? Each connection starts a new

> > > process on the server ???

> > >

> > > Is it possible to share connections with DELPHI through my 8 programs on

 a


> > > single client computer ????

> > >

> > > If I connect twice to the same database from one client, is it

 considered as


> > > 1 ou 2 connections ????

> > >

> > > what is a good max users connection configuration from your point of

 view???


> > >

> > > I hope you 'll understand my questions...

> > >

> > > Thanks in advance,

> > > Laurent

> >

> > Lets start with the basics.

> >

> > You provide not a single byte of information about the verion or edition

 of


> > Oracle, how you are connecting to the database, your hardware, your

 operating


> > system, or anything else that might help someone help you.

> >

> > But more critically I'm fascinated by the limit of 15 connections. Exactly

 how


> > was that achieved?

> >

> > Daniel Morgan

> >

>

>