Facebook Most Frequently Asked Latest Oracle Interview Questions Answers
What Is Cluster Key?
The related columns of the tables in a cluster are called the cluster key.
How Are The Index Updates?
Indexes are automatically maintained and used by Oracle. Changes to table data are automatically incorporated into all relevant indexes.
What Is An Oracle 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.
When A Query Is Sent To The Database And An Index Is Not Being Used, What Type Of Execution Is Taking Place?
A table scan.
What Is The Maximum Number Of Triggers, Can Apply To A Single Table?
12 triggers.
What Is The Output Of Sign Function?
1 for positive value,
0 for Zero,
-1 for Negative value.
What Are The More Common Pseudo-columns?
SYSDATE, USER , UID, CURVAL, NEXTVAL, ROWID, ROWNUM
What Are Pl/sql Cursor Exceptions?
Cursor_Already_Open, Invalid_Cursor
Any Three Pl/sql Exceptions?
Too_many_rows,
No_Data_Found,
Value_Error,
Zero_Error,
Others
To See Current User Name
Sql> show user;
If A View On A Single Base Table Is Manipulated Will The Changes Be Reflected On The Base Table?
If changes are made to the tables and these tables are the base tables of a view, then the changes will be reference on the view.
Can A View Be Updated/inserted/deleted? If Yes - Under What Conditions?
A View can be updated/deleted/inserted if it has only one base table if the view is based on columns from one or more tables then insert, update and delete is not possible.
What Are The Advantages Of View?
- To protect some of the columns of a table from other users.
- To hide complexity of a query.
- To hide complexity of calculations.
What Is Cycle/no Cycle In A Sequence?
CYCLE specifies that the sequence continue to generate values after reaching either maximum or minimum value. After pan-ascending sequence reaches its maximum value, it generates its minimum value. After a descending sequence reaches its minimum, it generates its maximum.
NO CYCLE specifies that the sequence cannot generate more values after reaching its maximum or minimum value.
Which Date Function Returns Number Value?
months_between
Display Odd/ Even Number Of Records
Odd number of records:
select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp);
1
3
5
Even number of records:
select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp)
2
4
6
What Is Cluster Key?
The related columns of the tables in a cluster are called the cluster key.
How Are The Index Updates?
Indexes are automatically maintained and used by Oracle. Changes to table data are automatically incorporated into all relevant indexes.
What Is An Oracle Index?
When A Query Is Sent To The Database And An Index Is Not Being Used, What Type Of Execution Is Taking Place?
A table scan.
What Is The Maximum Number Of Triggers, Can Apply To A Single Table?
12 triggers.
What Is The Output Of Sign Function?
1 for positive value,
0 for Zero,
-1 for Negative value.
 |
| Facebook Most Frequently Asked Latest Oracle Interview Questions Answers |
What Are The More Common Pseudo-columns?
SYSDATE, USER , UID, CURVAL, NEXTVAL, ROWID, ROWNUM
What Are Pl/sql Cursor Exceptions?
Cursor_Already_Open, Invalid_Cursor
Any Three Pl/sql Exceptions?
Too_many_rows,
No_Data_Found,
Value_Error,
Zero_Error,
Others
To See Current User Name
Sql> show user;
If A View On A Single Base Table Is Manipulated Will The Changes Be Reflected On The Base Table?
If changes are made to the tables and these tables are the base tables of a view, then the changes will be reference on the view.
Can A View Be Updated/inserted/deleted? If Yes - Under What Conditions?
A View can be updated/deleted/inserted if it has only one base table if the view is based on columns from one or more tables then insert, update and delete is not possible.
What Are The Advantages Of View?
- To protect some of the columns of a table from other users.
- To hide complexity of a query.
- To hide complexity of calculations.
What Is Cycle/no Cycle In A Sequence?
CYCLE specifies that the sequence continue to generate values after reaching either maximum or minimum value. After pan-ascending sequence reaches its maximum value, it generates its minimum value. After a descending sequence reaches its minimum, it generates its maximum.
NO CYCLE specifies that the sequence cannot generate more values after reaching its maximum or minimum value.
Which Date Function Returns Number Value?
months_between
Display Odd/ Even Number Of Records
Odd number of records:
select * from emp where (rowid,1) in (select rowid, mod(rownum,2) from emp);
1
3
5
Even number of records:
select * from emp where (rowid,0) in (select rowid, mod(rownum,2) from emp)
2
4
6