What is Secondary Index

While making the index, generally the index table is kept in the primary memory (RAM) and the main table, because of its size is keeps in the secondary memory (Hard Disk). Theoretically, a table may have millions of records (as the telephone directory of a large city), for which even a sparse index becomes so large in size that we cannot keep it in the primary memory. And if we cannot keep the index in the primary memory, then we lose the benefit of the speed of access. For very large table, it is better to classify the index in multiple levels.

 

Posted Date: 7/26/2013 7:00:39 AM | Location : United States

Ask an Expert

Related Discussions:- What is secondary index, Assignment Help, Ask Question on What is secondary index, Get Answer, Expert's Help, What is secondary index Discussions

Write discussion on What is secondary index
Your posts are moderated

Write your message here..

Related Questions

Can you delete data element, Can we delete data element, which is being use... Can we delete data element, which is being used by table fields. No we cant delete data element.

Explain the term - control as concurrent tasks, Explain the term - Control ... Explain the term - Control as Concurrent Tasks As we know, any object can be implemented as a task in programming language or operating system. This is the most general approa

Calculate the record size r in bytes, An employee record has the following ... An employee record has the following structure struct employee { int eno; char name[22]; float salary; char dept[10];}; (i) Calculate the record size R in bytes.

Transactions t1 and t2 are in a deadlock, Evaluate: a.When transactions... Evaluate: a.When transactions T1 and T2 are in a deadlock, one of the transactions will eventually implement to completion and let the other one continue implementation. b.

What is a hashing function, What is a hashing function?  What are the prope... What is a hashing function?  What are the properties of a good hashing function?  Describe the folding technique for hashing functions.      Ans:  Hashing function is a method

Write short notes on data ware housing, Write short notes on data ware hous... Write short notes on data ware housing? Data ware housing applications needs the transformation of data from many sources into a cohesive reliable step set of data configured a

Define the boyce-codd normal form, Define the Boyce-Codd Normal Form with i... Define the Boyce-Codd Normal Form with instance and also Compare BCNF and 3NF.  Ans: BCNF: For each functional dependency X->Y in a set F of functional dependencies over relati

Nested queries, Nested Queries Let us see some more complex queries in ... Nested Queries Let us see some more complex queries in this section. Sub-queries: Some of the basic concerns of sub-queries are: A sub-query is a SELECT statemen

Data replication, Data Replication "If a relation R has its copies kept... Data Replication "If a relation R has its copies kept at two or more sites, then it is considered replicated". But why do we replicate a relation? There are several advan

Differentiate oo development from structured development., Differentiate OO... Differentiate OO development from structured development. Structured approach of problem solving is based upon the idea of decomposition of system into subsystem. In this appro