Computer Security is the protection of computing systems and the data that they store or access.

1. Nizwa College of Technology
Assignment 2
26s1368
Submitted to: Ms. Kalivani
Submitted from: Hajer Mohamed Said Alriyami
Submitted date: 16/3/2017
Computer security
And
Session management

2. Nizwa College of Technology
Assignment 2
26s1368
INTRODUCTION
What is Computer Security?
Computer Security is the protection of computing systems and the data that
they store or access.
Why is Computer Security Important?
Computer Security allows the University to carry out its mission by:
 Enabling people to carry out their jobs, education, and research
 Supporting critical business process
 Protecting personal and sensitive information
Why do I need to learn about Computer Security? Isn't this just an I.T.
problem?
Good Security Standards follow the "90 / 10" Rule:
 10% of security safeguards are technical.
 90% of security safeguards rely on the computer user ("YOU") to
adhere to good computing practices
Example: The lock on the door is the 10%. You remembering to lock the
lock, checking to see if the door is closed, ensuring others do not prop the
door open, keeping control of the keys, etc. is the 90%. You need both parts
for effective security
What Does This Mean for Me?
 This means that everyone who uses a computer or mobile device
needs to understand how to keep their computer, device and data
secure.
o --> Information Technology Security
is everyone's responsibility!
 Members of the UCSC community are also responsible for
familiarizing themselves and complying with all University policies,
procedures and standards relating to information security --

3. Nizwa College of Technology
Assignment 2
26s1368
Security Objectives
 Learn "good computing security practices."
 Incorporate these practices into your everyday routine. Encourage
others to do so as well.
 Report anything unusual - Notify your supervisor and the ITS
 Support Center if you become aware of a suspected security incident
Sessionsand SessionManagement
Access Manager sessionmanagement refers to the process ofmanaging
the lifecycle requirements of a session, and notification of sessionevents
to enable global logout. Administrators can configure Access Manager
session lifecycle settings using the Oracle Access Management Console.
Here, we will look at several different tools and techniques for managing
sessions in the database.
Users are very important to a DBA in many ways, but first they are the
reason why there is need for a DBA. Users (either real or their electronic
counterparts) are what keep the database in motion. Managing sessions
means the DBA must monitor, tune and troubleshoot the entire
outstanding user's activity in the oracle instance. We have different faces
of database activity throughout the day, and over weeks, months, and
years. It looks like the same data behaving differently throughout a given
period, so there will be moments when the database is reported to
be slow, there will be times when the database apparently will hang, and
there will be other times when the database's performance will
look normalfrom the user's perspective. What is the reason why the
database's performance changes?
Monitoring, diagnosing, and troubleshooting sessions involve several
tools and techniques; specific sections of Enterprise Manager are focused
on session management, as we will see throughout this report. The
exposed tools behave the same on Unix like and Windows environments;
except the troubleshooting last resource, killing the session, which has
specific behaviors on Windows platforms due to the specific architecture
implementation, and we will have to deal with it by using the oracle tool.
In this context the user sessioncan either be a session generated by a real
user or by a program directed to perform some activity against the

4. Nizwa College of Technology
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database. This session can be connected either in dedicated or shared
mode.
User sessions in a dedicated server
architecture
When a user requests a remote connection to the database it must first
contact the listener. The listener redirects the request to the Oracle
Instance. This will spawn a new Oracle Server Process, which from now
on will be the process who will interface the user with the database; if the
connection to the database is local to the machine, it may be established
across the network or by Inter-Process Communication(IPC) , and the
Oracle server process will be spawned too. This Oracle server process
will be assigned to the user for the whole time the user remains attached
to the database. The new user sessionwill be assigned a Serial Number
and a SessionId. These are the numbers used to uniquely identify a user
connected to the database. The serial number guarantees that session-
level commands are applied to the correct sessionobjects in case a new
session is started with the same SID. A user session can be initially
monitored with the V$SESSION dynamic view.
The PMON background process registers the Oracle instance against
the Listener (in a self registration configuration), PMON registers
information about dedicated server processeswith the Listener. A User
Processstarts a connection against the Oracle instance by looking for
the Listener, the Listener redirects the user process to the oracle Server
Processand the dialog will be conducted from now on between the oracle
server process and the user process. Foreach active connection in

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Assignment 2
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a DedicatedServerArchitecture there will be one oracle Server
Processonthe hostmachine.
The connection through a dedicated server is the most widely used
connection mode in most Oracle databases.
Blocking sessions
When two or more different sessions compete for the same row
simultaneously, Oracle will immediately raise the lock enqueue
mechanism, which lets one process at a time modify the row. The lock
will be released once the transaction is finished (after a commit or
rollback command is issued). The first process that takes the row locks it,
meanwhile the other processes will have to wait. If this wait time is
visible to the user then it can be misinterpreted as a slow performance
problem.
Blocking sessions are issues that should be solved at the program level,
but in the mean time it is the DBA's responsibility to detect them and fix
them. A blocking sessionmay be normal during productiontime, this is
not the real problem. Oracle is prepared to queue sessions, the real
problem begins when a session hangs and leaves the other session
indefinitely waiting for the row lock to be released.
Code use:
Create sessionmangers limit
Create usermanger1 identified by 123;
Grant create sessionto manger1 identified by 123;
Alter user manger1 sessionmangers;
alter sessionmangers limit password_life_time 10/1440
password_grace_time 2/1440;

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create tablespaceschool_ts datafile 'c:tempschool.dbf' size 100M
extent management localautoallocate segmentspace management;
create temporary tablespace schooltemp_ts tempfile
'c:tempschooltmp.dbf' size 20M reuse extent management local
uniform size 10M;
alter user manger1 quota 500 on school_ts;
Reference:
https://www.safaribooksonline.com
http://its.ucsc.edu/policies/index.html
its.ucsc.edu/security/training/intro.html
https://docs.oracle.com/cd/E27559_01/admin.1112/.../session.htm