Re: Single Instance 4 Database - System is Slow?

<captain_2010_at_yahoo.com> wrote in message news:1121270021.948527.222440_at_g43g2000cwa.googlegroups.com...
> HI,
>
> I have oracle 8i installed on WindowsXp and
> running one instance with 4 Oracle Database.

hmm. what do you think 'a database' is, and how do you think you have 4 of them? If you really only have one instance then I'll bet you have 4 end-user schemas. it is of course equally possible you have 4 instances.

> Problem
> -------
> The system is running slow and I do not understand why it is slow ?

a good question would be 'what do you mean *exactly* by *the system is running slow*. Word takes a minute to display a blank page. a sql query that returns 1.8bn rows returns in 5secs instead of 1.

> Have tuned all parameters in init.ora have even increase blocked size
> still no improvement.

measured how. it will help your answer above.

> Planning for below action
> -------------------------
> Now planning to change mode from dedicated to share mode.
> Before changing to share mode wanted to know the effects of changing
> it.

You replace a single dedicated connection for each end user with a largely serialized connection pooling mechanism.

> Information gathered on dedicated and share mode
> ------------------------------------------------
> Though below are the few points that have been gathered
> 1) A dedicated server only serves one session.
> A shared server can serve many sessions.
> If there are going to be a large number of concurrent sessions, use
> shared server.

where large is typically measured in the thousands of concurrent end-users. WindowsXP is not a suitable platform for that sort of load.

> 2) Shared Server does two things:
> 1. It allows you to use some functionality that would not otherwise be
> available (like Connection Manager and connection pooling)

unless of course you are connection pooling anyway in the application.

> 2. It gets around resource shortfalls by having fewer processes at the
> back end.

not true for windows. there there would be fewer threads.

> 3) For long queries and transactions, dedicated servers will be more
> appropriate.

so you have many thousands of end-users connecting to 4 databases running on windowsXP all running really short transactions?

-- 
Niall Litchfield
Oracle DBA
http://www.niall.litchfield.dial.pipex.com