Sql Query To Compare Two Tables And Find Records With Matches

how to get matching records from two tables in oracle sql.
First  check the employee Records and check target records
for example i created  emp_target table  from emp with some duplicates in emp_target table.
Now Check the count of two table
SQL> SELECT COUNT(*) FROM EMP;

How to Uninstall Oracle 11g And Install Again in Windows7

How to Uninstall Oracle 10g in Windows7
 Uninstall all Oracle Components using the Oracle Universal Installer(OUI). but it is not appear in then follow below steps.
Step-1 
Go to Window Button -> click on it--> search for programs and Features.

Types Of Indexes In Oracle

• Index is an Object in Oracle. 
• It is a Performance Optimization Technique
• It speed up or increase the performance of the Query Execution.
• Index is creating automatically on Primary key and Unique Key.
• No need to create index for primary and unique keys columns.