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Oracle - What is the purpose of
Indexes? - Feb 23, 2010 at 11:00 PM by Rajmeet
Ghai
What is the purpose of Indexes?
An index is typically used to retrieve records of a table at a
faster rate. This is because an index contains value of the indexed
column.
Example:
The example below creates an index student_idx in
table student for column student_name
CREATE INDEX
student_idx
ON student
(student_name);
Oracle - What
is the purpose of Indexes? - April 10, 2009 at 11:00
AM
What is the purpose of
Indexes?
Oracle uses indexes to avoid the need for
large-table, full-table scans and disk sorts, which are required
when the SQL optimizer cannot find an efficient way to service the
SQL query.
Also read
What is an Index?, What are the objects in oracle?, What is
INDEX_BY_BINARY_INTEGER?, What is index and explain its purpose,
What are the guidelines to decide which table s to
index?..................
The list of all indexes in a schema can be obtained through the
USER_INDEXES view with a SELECT statement:...........
In a Bitmap index, a 2 dimensional array is created. The array
represents the index value multiplied by number of rows............
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