Thursday, November 20, 2014

Wednesday, November 19, 2014

What is domain,Administration Server ,Managed Server and Node Manager

What is domain in WebLogic ?

Domain is logical grouping of resources and services and consist of Administration ServerManaged Server and cluster.  There can only be one administration Server in domain and zero to N Managed Server.

What is Administration Server ?
Administration Server is WebLogic Server instance that maintains configuration data for a domain. You can deploy your application on administration Server but it is recommended to create managed Server and deploy your application in managed server and leave Administration domain for configuration and maintenance.

—There will always be atleast one Administration Server in a domain.

What is Managed Server ?
Any WebLogic Server instance apart from Administration Server is called asManaged Servers. This is weblogic server where you deploy your application (Though you can deploy your application in Administration server as well but it is not recommended in production/UAT instance)

What is Cluster in WebLogic ?
Group of WebLogic Managed Server Instances that work together to provide high availability and scalability for applications is called cluster. WebLogic Servers with in cluster can run on same machine or different machines. These are also called as managed Server cluster.

Start WebLogic Domain
Once you have successfully created domain, next step is to  start weblogic domain and access Administration Console. (Steps here are to start basic domain – only one Administration Server,  “Start/Stop WebLogic Server - Administration and Managed Server
Startup Script$BEA_HOME/user_projects/domain//bin/startWebLogic.sh (Unix)
$BEA_HOME\user_projects\domain\\bin\startWebLogic.cmd(Windows)
I installed domain with name base_domain and my BEA_HOME is c:\bea hence to start my domain -
c:\bea\user_projects\ domains\ base_domain\ bin\ startWebLogic.cmd

Node Manager is Weblogic Server utility to startstop and restartAdministration and Managed Server Instances from remote location.
1. Node Manager Process is associated with a Machine and NOT with specific Weblogic Domain (i.e. Use one node manager for multiple domains on same machine)
2. There are two versions of Node Manager - Java-based and Script-based
Java-based node manager – runs with in JVM (Java Virtual Machine) Process and more secure than script-based node manager. Configuration for java-based node manager are stored in nodemanager.properties
Script-based node manager – is available for Linux and Unix systems only and is based on shell script.
3. There are multiple ways to access Node Manager
From Administration Console : Environments -> Machines -> Configuration -> Node Manager
JMX utilities (Java Management eXtension)
WLST commands (WebLogic Scripting Tool)

Thursday, November 13, 2014

Installation of LOOKBACK ADAPTER on windows x86 platform (64 bit)

On Windows systems, install a loopback adapter on the single DHCP host that obtains an IP address from the DHCP server. This assigns a local IP address to your computer.
After installing the adapter, add a line to the %SYSTEMROOT%\system32\drivers\etc\hosts file with the following format, immediately after the localhost line:
IP_address   hostname.domainname   hostname
Replace IP_address with the local IP address of the loopback adapter.
Installing a Windows Loopback Adapter
To install a loopback adapter on Windows 2003 or Windows XP:
  1. Open the Windows Control Panel.
Windows 2003: Select Start > Control Panel > Add Hardware.
Windows XP: Select Start > Control Panel, then double-click Add Hardware.
  1. In the "Welcome" window, click Next.
  2. In the "Is the hardware connected?" window, select Yes, I have already connected the hardware, then click Next.
  3. In the "The following hardware is already installed on your computer" window, in the list of installed hardware, select Add a new hardware device, then click Next.
  4. In the "The wizard can help you install other hardware" window, select Install the hardware that I manually select from a list, then click Next.
  5. In the "From the list of hardware types, select the type of hardware you are installing" window, select Network adapters, then click Next.
  6. In the "Select Network Adapter" window, make the following selections:
    • Manufacturer: Microsoft
    • Network Adapter: Microsoft Loopback Adapter
  7. Click Next.
  8. In the "The wizard is ready to install your hardware" window, click Next.
  9. In the "Completing the Add Hardware Wizard" window, click Finish.
  10. If you are using Windows 2003, restart your computer.
  11. Right-click My Network Places on the desktop and choose Properties. This displays the Network Connections Control Panel.
  12. Right-click the connection that was just created. This is usually named "Local Area Connection 2". Choose Properties.
  13. On the "General" tab, select Internet Protocol (TCP/IP), then click Properties.
  14. In the "Properties" dialog box, click Use the following IP address and do the following:
    1. IP Address: Enter a non-routable IP for the loopback adapter. Oracle recommends the following non-routable addresses:
b.  192.168.x.x (x is any value between 1 and 255)
c.  10.10.10.10
    1. Subnet mask: Enter 255.255.255.0.
    2. Record the values you entered, which you will need later in this procedure.
    3. Leave all other fields empty.
    4. Click OK.
  1. In the "Local Area Connection 2 Properties" dialog, click OK.
  2. Close Network Connections.
  3. Restart the computer.
Removing a Windows Loopback Adapter
To remove a loopback adapter on Windows 2003 or Windows XP:
  1. Start the System Control panel.
Windows 2003: Select Start > Control Panel > System.
Windows XP: Select Start > Control Panel, then double-click System.
  1. In the "Hardware" tab, click Device Manager.
  2. In the "Device Manager" window, expand Network adapters. You should see Microsoft Loopback Adapter.
  3. Right-click Microsoft Loopback Adapter and select Uninstall.
  4. Click OK.

INFORMATICA SCENARIOS BASED QUESTIONS

Wednesday, November 12, 2014

Materialized Views

Materialized Views

Materialized views are disk based and update periodically base upon the query definition.

Views are virtual only and run the query definition each time they are accessed.

Materialized views can only be set to refresh automatically through the database detecting changes when
the view query is considered simple by the compiler. If it's considered too complex,
it won't be able to set up what are essentially internal triggers to track changes in the source tables
to only update the changed rows in the mview table.

When you create a materialized view, you'll find that Oracle creates both the mview and as a table

with the same name, which can make things confusing.

Why Use Materialized Views?

You can use materialized views to achieve one or more of the following goals:

1.Ease Network Loads.
2.Create a Mass Deployment Environment.
3.Enable Data Subsetting.
4.Enable Disconnected Computing.



EQ-
create MATERIALIZED  view user1
refresh complete 
START WITH SYSDATE
NEXT SYSDATE + 1
as select DISPLAY_NAME,OFFICE from wc_user_info_test1;

NOTE:-This MV is start from sysdate and next triggered fire for refresh is next day(sysdate+1).

-- First time refresh that is a complete refresh

SQL> BEGIN
2 dbms_mview.REFRESH('mv_test');
3 END;
4 /

PL/SQL procedure successfully completed.

SQL> SELECT last_refresh_type, to_char(last_refresh_date, 'hh24:mi:ss')
2 FROM user_mviews
3 WHERE mview_name = 'MV_TEST';

LAST_REFRESH_TYPE TO_CHAR(LAST_REFRESH_DAT
------------------------ ------------------------
FAST_PCT 21:13:34

Read-Only Materialized Views
CREATE MATERIALIZED VIEW hr.employees AS
SELECT * FROM hr.employees@orc1.world;

Updatable Materialized Views
CREATE MATERIALIZED VIEW hr.departments FOR UPDATE AS
SELECT * FROM hr.departments@orc1.world;



Hierarchies (Level-based hierarchy) in OBIEE 11G

Tuesday, November 11, 2014

OBIEE Architecture

OBIEE  Architecture






1)A Request is made by the users through answer and send it into Presentation server.
2)Presentation server convert request into Logical SQL and send it to Oracle BI Server.
3)Oracle BI Server  Convert Logical to Physical SQL and send it to database.
4)Now result get back to you.

Thanks



Data engineering Interview Questions

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