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

What are the features of embedded sql explain, What are the features of emb...

What are the features of embedded SQL? Explain. Embedded SQL - SQL could be implemented within two ways. It can be used interactively or embedded in a host language or throu

Derived horizontal fragmentation, Derived horizontal fragmentation: Some ap...

Derived horizontal fragmentation: Some applications may include a join of two or more relations. If the relations are stored at dissimilar locations, there may be a major overhead

Explain relevance of data dictionary in a database system, Explain the rele...

Explain the relevance of Data Dictionary in a Database System? Data dictionary is a database in its own right residing on the disk that consist of Meta data which is = Data abo

What is called remapping of bad sectors, What is called remapping of bad se...

What is called remapping of bad sectors? If the controller detects that a sector is injured when the disk is initially formatted, or when an attempt is made to write the secto

Describe the grant function and explain security, Describe the GRANT functi...

Describe the GRANT function and explain, how it associates to security. What kind of privileges may be granted? How are they revoked? Ans: Since more than one user can aacce

Differentiate between a subquery and a join, Differentiate between a subque...

Differentiate between a subquery and a join If we need to acquire information from one or more tables after that either subquery or join can be used. If the columns which are t

Give an example of multiple inheritance, Give an example of multiple inheri...

Give an example of multiple inheritance.  One example of multiple inheritance is a committee for students affair which include faculty and administrative staff member.

What is sql?, What Is Sql?  Structured Query Language (SQL) is a standa...

What Is Sql?  Structured Query Language (SQL) is a standard query language. It is usually used with all relational databases for data manipulation and definition. All the re

What is magnetic disks, What is magnetic disks?explain it? Magnetic dis...

What is magnetic disks?explain it? Magnetic disk provides the bulk of secondary storage of modern computer system. The disk capacity is growing at over 50% per year. But the st

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