Current Papers CS 614 Spring 2014 Solved By Humda Mcqsand Subjective Questions. Mit 4th SEM 25 Feb 2015

1. It is called a ______violation, if we have null values for attributes where NOT NULLconstraint exists

  • Load
  • Transform
  • Constraintpage 161
  • Extraction
  1. UAT stands for
  • User acceptance testing page 193
  1. Implementing a DWH requires ______integrated activities.
  • Tightly page 289
  • Loosely
  • Slackly
  • Lethargically
  1. The application development quality assurance activities cannot be completed until the data is ______
  • Stabilized page 308
  • Identified
  • Finalized
  • Computerized
  1. Normalization is a process of efficiently organizing data in a data base by ______a relational table into smaller table by projection.
  • Composing
  • Decomposing page 41
  • Joining/merging
  • Combining
  1. “Dirty data” class of anomalies include
  2. Lexical errors
  3. Integrity constraints violation
  4. Business rule contradiction
  5. Irregularities
  6. Duplication
  • i and iii and iv
  • i and ii and v
  • i and ii

Syntactically Dirty data: lexical errors, irregularities

Semantically dirty data: integrity constraint violation, business rule contradiction, duplication

Coverage anomalies: missing attributes, missing records

  1. Quality sold is stored as fact.
  • Additive
  • Non-additive
  • Association
  • Non-association
  1. Product selection phase fall in Kimball
  • Lifecycle Technology Track page 290
  • Lifecycle Data Track
  • Lifecycle Analytic Applications Track
  • None of the given
  1. Give least time to ____ can prove suicidal attempt of DWH project
  • OLAP
  • De-normalization
  • ETL page 313
  • None of the given
  1. Multandivision is the cotton hub
  1. Which is not an issue of “Click stream data”.
  • Identifying the Visitor Origin
  • Identifying the Session
  • Identifying the Visitor
  • Another option was given which is not issue of click stream.
  1. HTTP true statement
  • Is stateless page 364
  • Non world wide web protocol
  • Used to maintain session
  • Message routing protocol
  1. SMP stand forSymmetric Multi-Processing
  1. K-clustering is equal to sequence of n
  • K much greater than n
  • K much smaller than n
  • K is equal to square of n
  • None of the given
  1. The ith bit is set to 1, if ith row of the base table has the value for the indexed column. The statement refer to
  • Inverted
  • Bitmap page 233
  • Dense
  • Sparse index
  1. ______is a systematic sampling process that provides field specific information on pest pressure and crop injury.
  • Pest scouting page 333
  • Soil survey
  • Seed survey
  • Water survey
  1. In context of web data ware house. Which is NOT one of way to identify session
  • Using asynchronous session tracking protocol
  • Using Time-contiguous Log Entries
  • Using Transient Cookies
  • Using HTTP's secure sockets layer (SSL)
  • Using session ID Ping-pong
  • Using Persistent Cookies

Some mcqs from my midterm paper. 2 underlined MCQs are also included in my final paper

  1. The telecommunication data warehouse is dominated by the sheer volume of data generated at the call level ______area.
  • Subject page 35
  • Object
  • Aggregate
  • Details
  1. 4NF has an additional requirements which is
  • Data is in 3NF and no null key dependency
  • Data is in 2NF and no Multi value dependency page 48
  • Data is in 3NF and no multi value dependency
  • Data is in 3NF and no foreign key table
  1. 3NF remove even more data redundancy than 2NF but it is at the cost of
  • Simplicity and performance page 48
  • Complexity
  • No of table
  • Relations
  1. In full extraction, data extracted completely from source. No need to keep track of change to the ______
  • Data source page 133
  • DWH
  • Data mart
  • Data destination
  1. Which is not the characteristics of DWH
  • Ad-hoc access
  • Complete repository
  • Historical data
  • Volatile page 27
  1. Experienced showed that for a single pass of magnetic tape that scanned 100% of the record only______of the records.
  • 5% page 12
  • 30%
  • 50%
  • 80%
  1. HOLAP provides a combination of relational database access and “cube” data structures within a single framework. The goal is to get the best of both MOLAP and ROLAP:
  • scalability and high performance page 78
  1. ______are created out of the data warehouse to service the needs of different departments such as marketing, sales etc.
  • MIS
  • OLAPs
  • Data mart page 31
  • None of the given

Current Papers Spring 2014 solved By Humda For Finltrm Exams

  1. Write two unsupervised learning? page no. 270

Answer:

  • one way clustering
  • two way clustering
  1. Bitmap index: run length encoding ka ek question tha input di hoi output find out kerni thi Page no.234

Answer: If we apply Run length Encoding on the input “11001100”, the output will be

  • 12#02#12#02
  1. B-tree vs. hash indexes men se ye query di hoi thi

SELECT*FROM R WHERE A= 5 page no.228

Btana tha k is men dense index sparse index B-tree index and bitmap index men se konsi technique use ho gi aur explain kerna tha ise

  1. Identify kerna tha k ye statement correct he ya incorrect aur reason btana tha

Bayesian modeling is an example of unsupervised learning” page no 270

Answer: incorrect. Bayesian modeling is an example of supervised learning

Forward Proxy (2)

Answer: Ch#40 Page no: 369

The type of proxy we are referring to in this discussion is called a forward proxy. It is outside of our control because it belongs to a networking company or an ISP..

Drawbacks of waterfall model for DWH (3)

First and foremost, the project is likely to occur over an extended period of time, during which the users may not have had an opportunity to review what will be delivered.

Second, in today's demanding competitive environment there is a need to produce results in a much shorter timeframe.

In which scenario we can use waterfall (2)

The model is a linear sequence of activities like requirements definition, system design, detailed design, integration and testing, and finally operations and maintenance.The model is used when the system requirements and objectives are known and clearly specified.

How gender guide used.

If for very large number of records gender is missing, it would become impossible for us to manually check each and every individual‘s name and identify the gender. In such cases we can formulate a mechanism to correct gender. We can either use a standard gender guide or create a new table Gender_guide. Gender_guide contains only two columns name and gender. Populate Gender_guide table by a query for selecting all distinct first names from student table. Then manually placing their gender.

This table can serve us as guide by telling what can be the gender against this particular name. For example if we have hundred students in our database with first name equal to ‘Muhammad’. Then in our Gender guide table we will have just one entry ‘Muhammad’ and we will manually set the gender as ‘Male’ against ‘Muhammad’. Now to fill missing genders in exception table we will just do an inner join on Error table and Gender guide table.

run length encoding on these 2 ad-hoe the or output btana the .

Run length used in bitmap indexing

Output 1 may be

15#02# 18# (mean 1 come 5 time and 0 come 2 times and 1 come 1 8 times

(111110011111111))

Output 2 may be

11#01#11#

Output 3 may be

112#012#

Step of Kimball approach for data life cycle.

Kimball Process. Four step approach. (Business process-->Grains-->Facts-->dimension). He defines a business process as a major operational process in the organization that is supported by some kind of legacy system (or systems). (Read "Business Development Lifecycle") page see #290

Drawback of traditional web search. Ch: 39 page 351

1. Limited to keyword based matching.

2. Cannot distinguish between the contexts in which a link is used.

3. Coupling of files has to be done manually.

Two ways of session describe in World Wide Web.

Identifying the Session

  • Web-centric data warehouse applications require every visitor session (visit) to have its own unique identity
  • The basic protocol for the World Wide Web, HTTP, stateless so session identity must be established in some other way.
  • There are several ways to do this
  • Using Time-contiguous Log Entries
  • Using Transient Cookies
  • Using HTTP's secure sockets layer (SSL)
  • Using session ID Ping-pong
  • Using Persistent Cookies

MCQs

Execution will be terminated abnormally....(Quiz 4 file- 2 MCQs)

Kimball’s approach ...... driven(quiz 4 file-5 mcqs)

Pipeline per increase through..... (Quiz 4 file- 1 mcq)

Selectivity of query in olap...(Queries must be executed in a small number of seconds.)

star schema simplify ...

Majority of data ...fail if(Majority of projects fail due to the complexity of the development process.)

er is ...... design(constituted to optimize OLTP performance)

Survival of fittest is.....algorithm (Genetic Algorithms: These are based on the principle survival of the fittest. In these techniques, a model is formed to solve problems having multiple options and many values. Briefly, these techniques are used to select the optimal solution out of a number of possible solutions. However, are not much robust as can not perform well in the presence of noise.

Shipy in kobol develop...... (In 1972 theMitsubishi Shipyardsin Kobe developed a technique in whichcustomer wants were linked to product specificationsvia amatrix format. Technique is known today asThe House of Qualityand is one of many techniques of Quality Function Deployment, which can briefly be defined as “a system for translating customer requirements into appropriate company requirements”. The purpose of the technique is to reduce two types of risk. First, the risk that the product specification does not comply with the wants of the predetermined target group of customers. Secondly, the risk that the final product does not comply with the product specification

Q: 1brieflyexplains any two types of precedence constraints that we can use in DTS.

Answer: page 395

Precedence constraints sequentially link tasks in a package. In DTS, you can use three types of precedence constraints, which can be accessed either through DTS Designer or programmatically:

Unconditional:If you want Task 2 to wait until Task 1 completes, regardless of the outcome, link Task 1 to Task 2 with an unconditional precedence constraint.

On Success:If you want Task 2 to wait until Task 1 has successfully completed, link Task 1 to Task 2 with an On Success precedence constraint.

On Failure:If you want Task 2 to begin execution only if Task 1 fails to execute successfully, link Task 1 to Task 2 with an On Failure precedence constraint. If you want to run an alternative branch of the workflow when an error is encountered, use this constraint.

Q:2 Time complexity of K-means algorithm is O(tkn) what does t,k,and n represents here?

Page 281

Answer: Relatively efficient: O(tkn), where n is # objects, k is # clusters, and t is # iterations.

Normally, k, t n.

Q: 3 what are the problems you will face if low priority is given to cube construction?

Answer: page 313

Low priority for OLAP Cube Construction: Make sure your OLAP cube-building or pre-calculation process is optimized and given the right priority. It is common for the data warehouse to be on the bottom of the nightly batch loads, and after the loading the DWH, usually there isn't much time left for the OLAP cube to be refreshed. Asa result, it is worthwhile to experiment with the OLAP cube generation paths to ensure optimal performance.

Q: 4 List down any two parallel software Architectures?

Answer: Shared Memory, Shard Disk and Shared Nothing

Q: 5 what is unsupervised learning in Data mining?

Answer: page 27

Unsupervised learning where you don’t know the number of clusters and obviously no idea about their attributes too. In other words you are not guiding in any way the DM process for performing the DM, no guidance and no input. Unsupervised learning is closer to the exploratory spirit of Data Mining as small a stressed in the definitions given above. In unsupervised learning situations all variables are treated in the same way, there is no distinction between explanatory and dependent variables. However, in contrast to the name undirected data mining there is still some target to achieve. This target might be as general as data reduction or more specific like clustering. For unsupervised learning typically either the target variable is unknown or has only been recorded for too number ofcases.

Q: 6 which scripting language are used to perform complex transformations in Data packages?

Answer: Microsoft SQL Server provides graphical tools to build DTS packages. These tools provide good support for transformations. Complex transformations are achieved through VB Script or Java Script that is loaded in DTS package. Package can also be programmed by using DTS object model instead of using graphical tools but DTS programming is rather complicated.

Q: 7 "Dense index consist of a number of bit vector" justify it .

Answer Dense Index: Every key in the data file is represented in the index file. Bitmap index record (Value, Bit Vector): Bit Vector has one bit for every record in the file, ith bit of Bit Vector is set off record it has Value in the given column. Bit vectors typically compressed. Converted to sets of rids during query evaluation.

Q :8 It is essential: to have a sub-matter expert as part of data modeling team . What will be the implication if such expert isnot present in organization?

Answer: It is essential to have a subject-matter expert as part of the data modeling team. This person can be an outside consultant or can be someone in-house with extensive industry experience.Without this person, it becomes difficult to get a definitive answer on many of the questions, and the entire project gets dragged out,as the end users may not always be available

Suppose there is a large enterprise which uses the same server for the development and production environments. What problems can arise if it uses single server for both purposes? 5m

To save capital, often data warehousing teams will decide to use only a single database and a single server for the different environments i.e. development and production. Environment separation is achieved by either a directory structure or setting up distinct instances of the database.

This is awkward for the following reasons:

• Sometimes it is possible that the server needs to be rebooted for the development environment. Having a separate development environment will prevent the production environment from being effected by this.

• There may be interference while having different database environments on a single server. For example, having multiple long queries running on the development server could affect the performance on the production server, as both are same.

Write down any two drawbacks if “Date” is stored in text format rather than using proper date format like “dd-MMM-yy” etc. 5m

In context of Web data warehousing, consider the “web page” dimension, list at least five possible attributes of this dimension. 5m

Page key

Page source

Page function

Page template

Item type

Graphic type

Animation type

Sound type

Page file name

There are different data mining techniques e.g. “clustering”, “description” etc. Each of the following statement corresponds to some data mining technique. For each statement name the technique the statement corresponds to. 5m

a) Assigning customers to predefined customer segments (i.e. good vs. bad)classification
b) Assigning credit applicants to predefined classes (i.e. low, medium, or high risk) classification
c) Guessing how much customers will spend during next 6 monthsprediction
d) Building a model and assigning a value from 0 to 1 to each member of the set. Then classifying the members into categories based on a threshold value.Estimation
e) Guessing how much students will score more than 65% grades in midterm.Prediction

Specify at least one implication, if you don’t provide proper documentation as part of data warehouse development.3 m

Usually by this time most, if not all, of the developers will have left the project, so it is essential that proper documentation is left for those who are handling production maintenance. There is nothing more frustrating than staring at something another person did, yet unable to figure it out due to the lack of proper documentation.

Another pitfall is that the maintenance phase is usually boring. So, if there is another phase of the data warehouse planned, start on that as soon as possible.

In context of nested loop join, mention two guidelines for selecting a table as inner table. 3m

For a Nested-Loop join inner and outer tables are determined as follows: page 242

The outer table is usually the one that has:

• The smallest number of qualifying rows, and/or

• The largest numbers of I/Os required to locate the rows.

The inner table usually has:

• The largest number of qualifying rows, and/or

The smallest number of reads required to locate rows

We can identify the Session in Word Wide Web by using “Time-contiguous Log Entries” however there are some limitations of this technique. Briefly explain any two limitations. 3m

Answer: A session can be consolidated by collecting time-contiguous log entries from the same host (Internet Protocol, or IP, address). In many cases, the individual hits comprising a session can be consolidated by collating time-contiguous log entries from the same host (Internet Protocol, or IP, address). If the log contains a number of entries with the same host ID in a short period of time (for example, one hour), one can reasonably assume that the entries are for the same session.

Limitations:• This method breaks down for visitors from large ISPs because different visitors may reuse dynamically assigned IP addresses over a brief time period.

• Different IP addresses may be used within the same session for the same visitor.

• This approach also presents problems when dealing with browsers that are behind some firewalls.

Identify the given statement as correct or incorrect and justify your answer in either case.
"The problem of Referential Integrity always occurs in traditional OLTP system as well as in DWH". 3m

Answer:While doing total quality measurement, you measure RI every week (or month) and hopefully the number of orphan records will be going down, as you will be fine tuning the processes to get rid of the RI problems. Remember, RI problem is peculiar to a DWH, this will not happen in a traditional OLTP system.

There are two primary techniques for gathering requirements i.e. interviews or facilitated sessions. Which technique is preferred by Ralph Kimball? 2m

Bothhave their advantages and disadvantages. Interviews encourage lots of individual participation. They are also easier to schedule. Facilitated sessions may reduce the elapsed time to gather requirements, although they require more time commitment from each participant.Kimball prefers using a hybrid approach with interviews to gather the gory details and then facilitation to bring the group to consensus.