Oracle Interview Questions Part – 3

1.What are the components of physical database structure of Oracle database?

Oracle database is comprised of three types of files.One or more datafiles,two are more redo log files,and one or more control files.

2.What are the components of logical database structure of Oracle database?

There are tablespaces and database’s schema objects.

3.What is a Tablespace?

A database is divided into Logical Storage Unit called tablespaces.A tablespace is used to grouped related logical structures together.

4.What is SYSTEM tablespace and when is it created?

Every Oracle database contains a tablespace named SYSTEM,which is automatically created when the database is created.The SYSTEM tablespace always contains the data dictionary tables for the entire database.

5.Explain the relationship among Database,Tablespace and Data file.?

Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace .

6.What is schema?

A schema is collection of database objects of a user.

7.What are Schema Objects?

Schema objects are the logical structures that directly refer to the database’s data.Schema objects include tables,views,sequences,synonyms,indexes,clusters,database triggers,procedures,functions packages and database links.

8.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.

9.What is an Oracle view?

A view is a virtual table.Every view has a query attached to it.(The query is a SELECT statement that identifies the columns and rows of the table(s) the view uses.

10.What is Partial Backup?

A Partial Backup is any operating system backup short of a full backup,taken while the database is open or shut down.

11.What is pop list?

The pop list style list item appears initially as a single field (similar to a text item field).When the operator selects the list icon,a list of available choices appears.

12.What is the maximum no of chars the parameter can store?

The maximum no of chars the parameter can store is only valid for char parameters,which can be upto 64K.No parameters default to 23Bytes and Date parameter default to 7Bytes.

13.What are the default extensions of the files created by library module?

The default file extensions indicate the library module type and storage format .pll – pl/sql library module binary .

14.How do you display console on a window?

The console includes the status line and message line,and is displayed at the bottom of the window to which it is assigned .To specify that the console should be displayed,set the console window form property to the name of any window in the form.To include the console,set console window to Null.

15.What are the Coordination Properties in a Master-Detail relationship?

The coordination properties are Deferred,Auto-Query,These Properties determine when the population phase of block coordination should occur.

16.State any three mouse events system variables?

System.mouse_button_pressedSystem.mouse_button_shift .

17.What are the types of calculated columns available?

Summary,Formula,Placeholder column.

18.Explain about stacked canvas views?

Stacked canvas view is displayed in a window on top of,or “stacked” on the content canvas view assigned to that same window.Stacked canvas views obscure some part of the underlying content canvas view,and or often shown and hidden programmatically.

19.What is the difference between SHOW_EDITOR and EDIT_TEXTITEM?

Show editor is the generic built-in which accepts any editor name and takes some input string and returns modified output string.Whereas the edit_textitem built-in needs the input focus to be in the text item before the built-in is executed.

20.What are the built-ins that are used to Attach an LOV programmatically to an item?

set_item_property get_item_property (by setting the LOV_NAME property) .

21.What is Mirrored on-line Redo Log?

A mirrored on-line redo log consists of copies of on-line redo log files physically located on separate disks,changes made to one member of the group are made to all members.

22.What is Full Back up?

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.

23.What is the use of Control File?

When an instance of an ORACLE database is started,its control file is used to identify the database and redo log files that must be opened for database operation to proceed.It is also used in database recovery.

24.Do View contain Data?

Views do not contain or store data.

25.What are the Referential actions supported by FOREIGN KEY integrity constraint?

UPDATE and DELETE Restrict – A referential integrity rule that disallows the update or deletion of referenced data.DELETE Cascade – When a referenced row is deleted all associated dependent rows are deleted.

26.What are the type of Synonyms?

There are two types of Synonyms Private and Public.

27.What is a Redo Log?

The set of Redo Log files YSDATE,UID,USER or USERENV SQL functions,or the pseudo columns LEVEL or ROWNUM.

28.What is an Index Segment?

Each Index has an Index segment that stores all of its data

29.Explain the relationship among Database,Tablespace and Data file.?

Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace.

30.What are the different type of Segments?

Data Segment,Index Segment,Rollback Segment and Temporary Segment.