GDB of CS403 will be launched on 15th of July 2013 (15-07-2013) and will last for 48 hours only.

[Neha]

GDB_CS403_1 Dated: Jul 09, 13

Dear Students!

Please Note that GDB of CS403 will be launched on 15th of July 2013 (15-07-2013) and will last for 48 hours only.

The topic will be as follows:



A company is developing a database system containing information about cities, towns, and villages in the country. The number of cities, towns, and villages are in thousands and the database program should allow users to search a particular place by name. Users should also be able to search all places that match a particular value or range of values for attributes such as location or population size. This particular feature is known as a range query.



A reasonable database system must answer queries quickly enough to satisfy a typical user. For an exact-match query, a few seconds is satisfactory. If the database is meant to support range queries that can return many cities that match the query specification, the entire operation may be allowed to take longer. To meet this requirement, it will be necessary to support operations that process range queries efficiently by processing all cities in the range as a batch, rather than as a series of operations on individual cities.



Different indexing methods can be used to perform this operation. What will be your choice if:



a) database is created once and has no change over a period of time

b) database is created once and database is changed over a period of time





Justify your answer with appropriate logic.




Note: Try to provide precise, to the point answer and avoid irrelevant details.

[Neha]

i think wo hum se pochna chah raha hy k agar hum range quries m data search krna cha rahy hun tu hum konsa index method use kry gy agar hmary pas ek esa datbase hy jo k ek bar bna diya gya hy r is m koi change nai kr rahy r dosri situation ye k database bnaya gya lekin kuch arsy bad wo change ho jaye ga. n dono sortu m which one index method will be suitable 

[+ M.Tariq Malik]

Indexing

Extract specific information from data and access data through it

attributes, attribute vectors

Two step retrieval:
1)
hypothesis: search through the index returns all qualifying documents plus some false alarms
2)
verification: the answer is examined to eliminate false alarms

[2p4dl922mawrk]

Salam

bacho i think Sir ne kaha hai ap bto k agr part (a) ho to us k leiy kiya method use karte hain aur part (b ) k leiy kya mthod use ho ga i think asiy karna hai ye

[+ M.Tariq Malik]

Database Indexing Methods

Indexing based on

primary key: single attribute, no duplicates

secondary keys: one or more attributes

duplicates are allowed

indexing in M-dimensional feature spaces

Data and queries are vectors

retrieval: two step search approach

Primary Key Indexing

Dynamic indexing: the file grows or shrinks to adapt to the volume of data

good space utilization and good performance

Methods:

B-trees and variants (B+-trees, B*-trees)

Hashing and variants (linear hashing, spiral etc.)

hashing is faster, B-trees preserve order of keys

B-trees, hashing are the industry work-horses

Secondary Key Indexing

Much interest in multimedia

signals are represented by feature vectors

feature extractioncomputes feature vectors from signals

The index organizes the feature space so that it can answer queries on any attribute

[malik asim masood]

A point k lye koi aur method use ho ga and B point k liye koi aur.. is it right??? i found clustered index better to perform that range query task.. Please correct me if em wrong :(

[+ sam]

2nd one is best

[2p4dl922mawrk]

Sam 2on per likhna kese kam karne gay 2on Part A aur Part B

[+ sam]

last pa sir n jo condition di hui hain ma na un ma sa kha ha 2nd one jis m chaning ki option ho wo best ha

[Muhammad kashif]

sam read the GDB carefully

[+ sam]

to 2nd option yahi ha na 

b) database is created once and database is changed over a period of time

to merya khayal ma ya best ha

[Neha]

ok dear waiting 

[Muhammad Ehtasham]

thanks