1. What is hot backup?
A hot backup is basically taking a backup of the database while it is still up and running and it must be in archive log mode.
2. What is the advantage of hot backup?
The main benefit of hot backup is that you can use the database even though backup is occurring .
3. What Is cold backup?
A cold back up is basically taking a backup of the database while it is shutdown and it doesn’t require being in archive log mode.
4. What is the advantage of cold backup?
The main benefit of cold backup is that there will be slight performance gain as database is not cutting archive logs to disk.
5. How do you switch from an init.ora file to spfile?
By issuing create spfile from pfile command
6. What is datablock?
The smallest unit of logical storage for a database object is called Datablock.
7. What is an extent?
The chunks of additional storage contiguous data block groupings are called extents
8. What is a segment?
All the extents that an object takes when grouped together is called segment.
9. Where would you look for errors from the database engine?
The errors from the database engine are looked In the alert log.
10. What is ARCHIVELOG mode?
ARCHIVELOG is a mode that puts a database in creating a backup of all transactions so that it can recover at any point in time.
11. What is NOARCHIVELOG mode?
NOARCHIVELOG mode is complete replica of ARCHIVELOG mode in which it doesn’t have advantage of not having to write transactions to an archive log which increase the performance of database.
12. Mention the different stages of instance startup to a usable state where normal users may access it
STARTUP NOMOUNT- Instance startup
STARTUP MOUNT- The database is mounted
STARTUP OPEN- The database is opened.
13. How can you encrypt a PL/SQL application?
By using WRAP command we can encrypt a PL/SQL application.
14. What is the use of Table Functions?
Table Functions are designed to return a set of rows through PL/SQL ,but intended to be used as a normal table or view in a SQL statement.
15. Mention the different advisory statistics?
Buffer Cache Advice, Segment Level Statistics and Timed Statistics are three advisory statistics.
16. Where is tree structure and audit traces placed in Oracle directory?
The tree structure and audit traces are placed in Oracle directory of In Unix $ORACLE_HOME/rdbms/audit, in Windows the event viewer.
17. What are materialized views?
Materialized views are objects that reduce the sets of information that have been summarized, grouped or aggregated from base tables.
18. What are the uses of materialized views?
Materialized views are used in data warehouse or decision support systems.
19. Mention two methods that determine the DDL changes?
Logminer and streams are the methods that determine the DDL changes.
20. What is the use of coalescing a table space?
Coalescing is only valid for dictionary-managed tablespaces and de-fragments space by combining neighboring free extents into large single extents.
21. What is Temporary tablespace ?
Temporary tablespace is used for temporary objects such as sort structures.
22. What is Permanent tablespace?
Permanent tablespace are used to store objects meant to be used as true objects of the database.
23. What is Partitioning?
Partitioning is a method of taking large tables and indexed and splitting them in to smaller, more manageable pieces.
24. Mention the names of the two files used for network connection to a database?
TNSNAMES.ORA and SQLNET.ORA are the two files used for network connection to a database.
25. Mention the different Oracle utilities used for loading data in to the database?
SQL*Loader and IMPORT utilities are used for loading data in to the database.
26. How will you enforce the security using stored procedures?
Grant the ability to access the procedures that access the tables and don’t grant user access directly to tables with in the application.
27. Mention the different options to refresh snapshots?
COMPLETE,FAST and FORCE are three options available to refresh snapshots.
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