Qs for ORACLE GURUs

Hi All,

I herewith like to place you a Qs which made me to think a lot.
Assume that you have one instance on a server and the instance in down.

Now,from svrmgrl if u say connect internal it will connect as sys user.

Now my Qs is :
Where that internal connects???
How it connects?
When u want to startup and instance you are going to set ORACLE_SID,ORACLE_HOME.

When the database is down,If u connect as internal will you get a msgs as "connected"?where and how ?

Reply me if any one gets answer.
Regards,
Vinod

Hm... dunno on Unix but on NT the Service has to be running, and I guess that the connect somehow connects to that:- If the service isnt running I dont think you get that far even. As to Unix....no idea as theere is no process running to connect to....

Hi Vindod,

Here are some or the answers

Where that internal connects???

I think Internal connects to an idle instance if the database is not up if the database is up it connects to the public schema of your oracle database.

How it connects?

Connects thru a service on NT/2000 or Process in Unix

When the database is down,If u connect as internal will you get a msgs as "connected"?where and how ?

Yes you will get a message as connected when the database is down.Try this

set oracle_sid=youroraclesid

Invoke server manager

svrmgr> connect internal

You will be able to connect to internal if you are a part of the DBA group on Unix and part of the ORA_DBA group on NT/2000 it will not prompt for a password

From oracle 8i you can use sqlplus to startup and shutdown the database also

Hope this helps

Regards

Hi Santosh,bmycroft,

Thanks for your reply.

Let me know to the which process it connects on Unix.

A instance is an combination of Memory and the background process ,,,,is in it.

In that case,As per the above reply u have said it will connect to idea instance?Whatz this Idle Instance?

When no SGA and Background process is running then...(when database is down)howz this proceedure is done.

Let me know the answer at the earliest.

Regards,
Vinod

Hi,

It's get connected to SID only,
The SID is a site/system identifier. SID plus the Oracle_home are hashed together in Unix to create a unique key name for attaching an SGA. If your Oracle_sid is not set
correctly, you'll get "oracle not available" since it cannot
attach to a shared memory segment that is identified by magic key. On NT, we don't use shared memory but the SID is still important. We can have more then 1 database on the same oracle home so we need a way to id them.


Vicky

Hi Vicky,

Thanks for your reply.But U have answered something irrelvent.Kindly read this thread from the starting.

Thanks
Vinod

Hi Vinod,

Here are your answer's ...

There are two main administrative privileges in Oracle: SYSOPER and SYSDBA
These are special privileges as they allow access to a database instance even when it is not running and so control of these privileges is totally outside of the database itself.

SYSOPER privilege allows operations such as:
Instance startup, mount & database open ;
Instance shutdown, dismount & database close ;
Alter database BACKUP, ARCHIVE LOG, and RECOVER.
This privilege allows the user to perform basic operational tasks without the ability to look at user data.

SYSDBA privilege includes all SYSOPER privileges plus full system privileges (with the ADMIN option), plus 'CREATE DATABASE' etc.. This is effectively the same set of privileges available when previously connected INTERNAL.

Internal get connected to instance through ORACLE.EXE and
since the control of this privileges is totally outside the database, it doesn't matter whether database is up or down.



Regards,
Vicky

Hi Vicky,

Thanks for your reply.I can understand that SYSOPER AND SYSDBA are the Administrative privilages.

The Internal user has both but,I dont think it connects to ORACLE.EXE as i have not seen ORACLE.EXE anywhere.

Normally when u connect as internal it will connect as sys user in the database.

Regards,
Vinod

Hi,
Imagine the DB is down. At svrmgrl when u say connect internal it will connect to an idle instance. (A location in the memory) This name is taken from the env variable $ORACLE_SID.
before connecting kindly issue the foll command on unix :-
echo $ORACLE_SID . this will give u the sid identifier. Similarly echo $ORACLE_HOME will give u the Oracle Home directory path. When you say startup, Oracle will look for initSID.ora in Oracle Home or init.ora and eventually your SGA is initialised and DB is started. Hope that would suffice.

Cheers

Check
$cd $ORACLE_HOME/bin
$ls -l | grep oracle

you will get ORACLE file


Regards,
Vicky