Oracle Questions and Answers
1. What is Oracle table?
|A table is the basic unit of data storage in an Oracle database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.|
2. What is schema?
|A schema is collection of database objects of a user.|
3. How to check errors from plsql package not by log file not by "show err"from sql * plus provided concurrent program name
|Use Exceptions for Error Handling|
4. What is normalization? What is the advantage of normalization?
|Normalization is the process of removing redundant data from your tables in order to improve storage efficiency, data integrity and scalability|
5. What is the difference between rownum,rowid
|rowid has a physical significance i.e you can read a row if you know rowid. It is complete physical address of a row. While rownum is temporary serial number allocated to each returned row during query execution.|
6. What is an Index Segment ?
|Each Index has an Index segment that stores all of its data|
7. What is clusters ?
|Group of tables physically stored together because they share common columns and are often used together is called Cluster|
8. What are roles? How can we implement roles ?
|Roles are the easiest way to grant and manage common privileges needed by different groups of database users. Creating roles and assigning provides to roles. Assign each role to group of users. This will simplify the job of assigning privileges to individual users.|
9. What is default tablespace ?
|The Tablespace to contain schema objects created without specifying a tablespace name.|
10. What is Full Backup ?
|A full backup is an operating system backup of all data files, on-line redo log files and control file that constitute ORACLE database and the parameter.|