What is Index and different types of Indexes?
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Answer / alcheringa
indexes is a process of creating a structure from a
database table from a single or multiple compostion
(atleast) of attributes for efficient data retreival.
some database even allow to create indexes out of
expressions as well.
there are different types of indexes based on the
implementation methodology:
b Trees, b+ trees, bitmap indexes, hash index etc . infact
in some database the index file is different from the
database file and hence one can write one's plug in for a
special kind of index .
clustered and non-clustered is the kind of architecture
that is used to define the index methodology as noted
earlier.
indexes are boon when used in retreivals and they are
doomed when used in situations where there's more write
than read. this is so because every new write in the table
also implies corresponding modofication in the indexes as
created for the table.
| Is This Answer Correct ? | 22 Yes | 5 No |
Answer / elbert gopta
An index is an additional auxiliary access structure used to speed up the retrieval of records in response to certain search conditions
An index enables efficient access to a record based on the indexing field or fields
An index is an ordered file with two fields consisting of the indexing field and the physical address of the record/block
Each table typically has a primary index created for the primary key of the table.
Types:
Primary Index
Secondary Index
Multilevel indexes
B-tree and B+-tree indexes
| Is This Answer Correct ? | 13 Yes | 5 No |
Index is used to fetch the data in a reliable and fast
manner and the types of index avalilable are clustered
index and non clustered index.
Murali
dharanmu@yahoo.com
| Is This Answer Correct ? | 13 Yes | 8 No |
Answer / manvendra
PHYSICAL OR LOGICAL LISTING OF COLUMN TO SPEEDUP THE SEARCH
IN A TABLE OR VIEW IS CALLED INDEX.
FUNCTION BASED INDEX
HASH INDEX
BITMAP INDEX
COMPOSIT INDEX
B TREE INDEX
| Is This Answer Correct ? | 8 Yes | 9 No |
Answer / akriti sengar
in index we can write the summary of anything in a tabular form.
there are different type of indexes are as follows.
1.b trees
2.b+trees
3.bitmap indexes
| Is This Answer Correct ? | 4 Yes | 6 No |
Answer / joe
4 different types of index
1.Clustered
2.Non Clustered
3.Primary XML
4.Spatial
| Is This Answer Correct ? | 1 Yes | 5 No |
Index is used to solve some query fast.
we have 2 types of cursors.
1 Bitmap Index ( used only on Low cardinality columns)
2. Btree Index ( used only for High Cardinality of
columns)
| Is This Answer Correct ? | 8 Yes | 18 No |
what are the diffeenes between oracle 9i,oracle 10g
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