Tuples-attributes , Database Management System

Assignment Help:

Consider a relation s over the attributes A and B with the following characteristics:

  • 5,000 tuples with 10 tuples per page
  • A 2-level B+ tree index on attribute A with up to 100 index entries per page
  • Attribute A is a candidate key of s
  • The values that the attribute A takes in relation s are uniformly distributed in the range 1to 100,000.

(a)    Assuming that the aforesaid index on A is unclustered, estimate the number of disk accesses needed to compute the range query σA>1000 ^ A<6000 (s).

(b)   What would be the cost if the above index were clustered? Explain your reasoning.

 


Related Discussions:- Tuples-attributes

Although how will the system recover, Although how will the system recover ...

Although how will the system recover The selection of REDO or UNDO for a transaction for the recovery is completed on the basis of the state of the transactions. This state is

Set concept is used in which type of modelling, SET concept is used in whic...

SET concept is used in which type of modelling? SET concept is used in Network Model.

Database errors, Database Errors: An error is said to have occurred if the ...

Database Errors: An error is said to have occurred if the implementation of a command to manipulate the database cannot be successfully finished either due to inconsistent data or

Write short notes on relational model, Write short notes on relational mode...

Write short notes on relational model The relational model uses a collection of tables to show both data and the relationships between those data. The relational model is an ex

What are the benefits of decomposing a system, What are the benefits of dec...

What are the benefits of decomposing a system? The benefits of decomposing a system into subsystems are that after decomposition, each individual component become smaller and e

Defining internal classes and operations, Defining Internal Classes and Ope...

Defining Internal Classes and Operations When we enlarge algorithms, new classes can be added to the store intermediate results. A complex operation could be looked at, as a c

Problems of concurrent transactions-lost updates, Lost Updates : Suppose th...

Lost Updates : Suppose the two transactions T3 and T4 run simultaneously and they happen to be interleaved in the following way (suppose the initial value of X as 10000):

Advantages and drawbacks of ddbms, Advantages And Drawbacks Of Ddbms  T...

Advantages And Drawbacks Of Ddbms  There are various reasons for building distributed database systems, with sharing of data, reliability and availability, and speedup of query

Prove that a relation which is 4nf must be bcnf, Prove that a relation whic...

Prove that a relation which is 4NF must be BCNF.   Ans Let R be in 4NF.  Suppose it is not in BCNF.  Hence, there exists an FD X→Y in R such that x is not a super key. Although

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd