Install JDK / JRE in Oracle Linux / RHEL

To install Java in RHEL or Oracle Linux based Desktop machine, open a browser and navigate to Java SE official download page and grab the latest .rpm binary package in your system.

Install Java JDK / JRE 

After Java .rpm file download completes, navigate to the directory where Java package has been downloaded and install Java JDK/JRE by issuing the below command

# yum install jdk-<Version>_linux-x64_bin.rpm

# yum install jre-<Version>_linux-x64_bin.rpm

Setup Java Environment Variables

Next, insert Java environment variables and executable files path into your system $PATH variable by issuing the below commands
This method ensures that Java environment variables and executable will be accessible system wide

-------- Set JAVA_HOME and Path Variable JDK -------- 

# export JAVA_HOME=/usr/java/jdk-<Version>
# export PATH=$PATH:/usr/java/jdk-<Version>/bin

-------- Set JAVA_HOME and Path Variable JRE --------

# export JAVA_HOME=/usr/java/jre-<Version>
# export PATH=$PATH:/usr/java/jre-<Version>/bin

Check Java JDK / JRE Version

# java --version
java <Version{
Java(TM) SE Runtime Environment (build <Version>)
Java HotSpot(TM) 64-Bit Server VM (build <Version>, mixed mode)

OLEDB provider "OraOLEDB.Oracle" for linked server

SQL Server Linked Server to Oracle Fails with Cannot Initialize Data Source Object error

You have a running SQL Server and you need to create a linked server to Oracle.
You follow these steps

Install Oracle client in the SQL Server
Setup tnsnames.ora and sqlnet.ora files
Test connection to Oracle using tnsping and sqlplus
Add Linked Server

Now when you test it, you get a long error message saying

Cannot initialize the data source object of OLE DB provider "OraOLEDB.Oracle" for linked server "ORATEST"
OLEDB provider "OraOLEDB.Oracle" for linked server "ORATEST" returned message "ORA-12154: TNS: Could not resolve the connect identifier specified". (Microsoft SQL Server, Error: 7303)

This has been an issue with Linked Server to Oracle from the beginning of time. SQL Server does not see Oracle driver after you install it until you restart the SQL Server.

Restart your SQL Server service your linked server will start working.