Answer / rudrab123

An index is a listing of keywords accompanied by the
information of location of the subject.
in a SQL statement, if there is no Where clause then there
is no index.

In Oracle 8i,
there are 4 types of indexes .They are:-
1.B-Tree Index
2.Bitmap Index
3.Unique index
4.Function based index.

Answer / rudrab123

Answer 1 is not he basic function of Index in Oracle or any
databse.
Generally speaking,attaching index to a column in a table,
information of the location of the different values in the
indexed column is also provided.This address is like the
pointer varible in C,and in SQL it is called ROWID(a
pseudocolumn).Let us see he example ....

SQL>select * from students
where id=123;
Students is a databse table and ID is the column in the
table on which we create the index.

On execution of the above query, at first, the ROWID
corresponding to id=123 in students table is found.From
this rowid, the index value for the row of data which is
pointed to by ROWID is found(in very less time).And so the
row is idenified and the entire row data is displayed.
The above serach process is specifically called "TABLE
ACCESS FULL(USING ROWID)).

Answer / guest

when queries are run against a DB,an index on that DB
basically helps in the way the data is sorted to process
the query for faster data retievals.

There are basically two types of indexes that we use in SQL
Server. Clustered and the Non-Clustered.

Answer / bhargav kesavan

Indexes are used to do a faster search. i.e; easy way to
retrive data.

There are two types are indexes:
1> B-Tree Indexes.
2> Bitmap indexes.

Answer / ted

There are four types index:

1)Bitmap index
2)Dense index
3)Sparse index
4)Reverse index

Answer / a.brahmam

indexes 5 tyeps
1.B-Tree index:-->in oracle by default index is called B tree index.
2.Bit map index:--->in oracle Bit map index is used to data warehouse applications generally Bit map index created low cardinality columns.
3.function based index:--->B tree index extension of the function based index.
in B tree indexes two type this are
4.Unique B tree index in oracle by default automatically created.
5.Non-Unique B tree index in oracle by default manually created.

Answer / test

Index simply means sorting of data. Let u stake an example :

EmpID Name
1 A
6 B
5 C
9 D
...
...
2 ZZ

Now if we create index (Talking about btree index) on EmpId
it means creating a segment with the following in sorted
order
EmpId Rowid
1 <some value>
2 ....
5 ...
6 ...
...

Now if we want to search with EmpId, it will do a binary
search and get the rowid in few searches

Give the constructs of a package, function or a procedure.

0 Answers  

What is the quickest way to fetch the data from a table?

0 Answers  

How to write a query with a full outer join in oracle?

1 Answers  

What are the values that can be specified for OPTIMIZER_GOAL parameter of the ALTER SESSION Command ?

1 Answers  

how do we code triggers , store procedure , Performance tuning and indexing in a Java Project? Pls kindly get me the perfect answer with the code for each....thank you in advance............pls any body kindly help me soon as possible....

0 Answers  

What is java oracle used for?

0 Answers  

Which of the following is not a database object TABLESPACE TABLE INDEX NONE

1 Answers  

what is the bitmap index?

3 Answers  

What is difference between SUBSTR and INSTR?

1 Answers  

I have a table emp. There is only one column in the table. In that , there are only three rows in that column. The value in the first row is 'A' and the value in the second row is 'B' and the third row is 'C'. Now, my question is , How will you write a select query to display the output as B C A Note: order by cannot be used coz it gives us output as CBA. But the output should be BCA.

4 Answers  

SELECT * FROM (SELECT TITLE FROM MOVIE ORDER BY RANK DESC) WHERE ROWNUM > 4; when i run the above query .it produces output as NO ROWS SELECTED.why ?plz any one help me

6 Answers   TCS,

what are different types of deletes?

1 Answers