Computer Tutorials
Earn Money From Internet
Cheap Freelancers
Ask An Expert
Register Cheap Domain
Data Recovery
Best Mutual Funds
Trading Forex Online
Cheap Web Hosting
Ajax Tutorials
Cheap Cell Phone Plans
Free Mobile Learning
Job Portal
Photoshop Tutorials
Cheap Jewelry
Cheapest Air Travel
Oracle Interview Questions And Answers
|
Page 2 of 95
12. Do View contain Data ? Views do not contain or store data. 13. Can a View based on another View ? Yes. 14. What are the advantages of Views ? Provide an additional level of table security, by restricting access to a predetermined set of rows and columns of a table. Hide data complexity. Simplify commands for the user. Present the data in a different perpecetive from that of the base table. Store complex queries. 15. What is a Sequence ? A sequence generates a serial list of unique numbers for numerical columns of a database's tables. 16. What is a Synonym ? A synonym is an alias for a table, view, sequence or program unit. 17. What are the type of Synonyms? There are two types of Synonyms Private and Public. 18. What is a Private Synonyms ? A Private Synonyms can be accessed only by the owner. 19. What is a Public Synonyms ? A Public synonyms can be accessed by any user on the database. 20. What are synonyms used for ? Synonyms are used to : Mask the real name and owner of an object. Provide public access to an object Provide location transparency for tables,views or program units of a remote database. Simplify the SQL statements for database users. 21. What is an Index ? An Index is an optional structure associated with a table to have direct access to rows,which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table. 22. How are Indexes Update ? |