Re: parallel instances

On Fri, 28 Jan 2005 09:23:10 GMT, "b c via OracleMonster.com" <forum_at_OracleMonster.com> wrote:

>Thank you for your swift replay. Firstly excuse me for the loose terminology. Your guess is a correct restatement of the issue I am confronted with.
>
>Being new to the technical site of windows services, I had a hunch that my services that are not running do not to have any performance impact. I just was not sure. My hunch is now confirmed. Thanks.
>
>
>By two "parallel" instances I mean two separate instances installed on the same server. In my case they are even installed on the same disk.
>I am running these Oracle 8.1.7.4 instances on a Win2000 server. At this time the most specific problems is the lack of internal memory 640 Mb where 1 Gb is a minimal requirement and not being connected to the backbone. we are adressing these problems at this time. I'll let you kow what happens after this has been solved.
>
>Thanks.

OK, let's clarify this a bit more. You have created two separate databases. Let's call them mydb1 and mydb2. So, first, somewhere on you disk you should have one or more directories call <something>\<something>\MYDB1 and <something>\<something>\MYDB2. In those directories you should find the files that make up the respective databases. Remember, the *database* is just a particular set of files on disk. No magic there.

Second, in your Windoze Services you should find a series of services called OracleSomethingSomething. Specific examples are things like

OracleOraHome92Agent
OracleOraHome92TNSListener

and specificly

OracleServiceMYDB1
OracleServiceMYDB2

Now, a database "instance" is a set of processes that mounts the *database* (the set of files) and manages the flow of data to and from those files. In the Windoze world, those services mentioned above essentially constitue the instance. If they are stopped, you have no instance, you just have a set of files, with no more performance impact than a readme.txt file. Even if those services are started, you may or may not have much going on, depending on if the instance itself has started. In Windows, it's a fine distinction between the Oracle instance and the Windows service that supports it.

I would strongly suggest you go to otn.oracle.com and sign up for a free account. Then go to tahiti.oracle.com where you will find the complete doc set in both html and pdf format. The totality of the docs can be pretty daunting in volume, but the Concepts manual is *must* reading for anyone trying to manage an Oracle db.

It's unclear if you created one instance/db and had acceptable performance that then went south when you created the second, or if you simply created both and then discovered that performance was lousy from the git-go.

While 640mb is not considered a whole lot by todays standards, it's still not bad for a 'test' box, which yours apears to be. Where did you get the idea that 1gb was a minimum requirement? Thanks.

• Ed Stevens

Cohn's Law: The more time you spend in reporting on what you are doing, the less time you have to do anything. Stability is achieved when you spend all your time doing nothing but reporting on the nothing you are doing. Received on Fri Jan 28 2005 - 07:41:34 CST