what are indexes..how many types of index's are there and
what are they?
Answer Posted / 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)).
| Is This Answer Correct ? | 3 Yes | 2 No |
Post New Answer View All Answers
In what script is snap$ created? In what script is the scott/tiger schema created?
How to drop a tablespace?
How can I create database in oracle?
How to use "while" statements in oracle?
What happens if you use a wrong connect identifier?
What is a tns file?
Is truncate autocommit in oracle?
How many data types are supported?
What is bind variable in oracle 11g?
What do you understand by database schema and what does it hold?
Please send me Informatica 8.1 certification dumps, my mail id mona85gupta@gmail.com
What is the difference between substr and instr?
Database crashes. Corruption is found scattered among the file system neither of your doing nor of Oracles. What database recovery options are available? Database is in archive log mode.
Explain an index segment?
How to run create database statement again?