Post NET Blues

Hello Friends!

The result of CBSE-UGC NET July-2018 examination was declared recently. With their hearts beating faster than usual, candidates logged into the site to find if the luck favoured them or not. Many of the blessed ones were on Cloud Nine after reading their score and the Golden words "You are qualified for Assistant Professor/JRF" After all, their hard work has finally paid them.

I congratulate to all my friends who have qualified the exam and wish them a bright career ahead.

This post, however, is for those friends for who the result was not this sweet and perhaps they missed the bull's eye by a margin. I can empathise with them. I faced these Post-NET Blues many a times. This reminds me of the times when UGC NET was conducted by UGC itself (before this job was handed over to CBSE). Then, the list of the Roll Nos. of qualified candidates was published on UGCNETONLINE website. I would open the link with anxious hands and search for my Roll No. but without success.

I then, would check the final answer keys released by UGC with my keys and note down the questions which could be challenged even after the final result declaration. I would then research such tricky questions on Internet till late night to find any hopes of wrong keys.

This situation was very depressing for me. The night of NET result was always sleepless for me. I would then think of many "final" ideas like:
  "This NET is very hard nut (for me) to crack."
   "I have no strong academic foundation to prepare for it."
   "The number of qualified persons in my subject is increasing and it is going to be difficult to find a suitable teaching job without NET."
  "I must change my line and either I must prepare for other competitive exams or I should better apply for school jobs."
" I have already attempted for so many times and the level of exam is getting tougher. So it is now going out of my limits."
   "I am married and have many family and work responsibilities. I have no much time to do my studies. How I can clear the exam?" etc. etc.

I am sure that some of you must have such thoughts on their minds after seeing their result. Believe me, you are among thousands of the candidates who have now got one or more of the "reasons" to say "Good-bye" to their NET hopes. But before these gloomy thoughts take control over your dream of NET qualification, stop yourself. Rather than letting it drown you into self-pity or anger, decide to get out of this mood and give yourself a break. Go for a small vacation or do shopping or go for a movie with friends or whatever you like.

When you are back to your daily routine and are feeling good, make a strategy on how to bell this cat called NET. I have 2-3 posts on this blog where I have shared my experience on how one can qualify the exam. You may check these posts:
1. http://ugcnet-notes.blogspot.in/2015/07/how-to-ensure-great-score-in-net-exam.html
2. http://ugcnet-notes.blogspot.in/2016/04/recipe-for-cracking-UGC-NET.html
3. http://ugcnet-notes.blogspot.in/2016/07/prepare-but-dont-stress.html

I am sure that hard work accompanied with persistence and patience will take you to the places where you have always wanted to go.

Wish you all a Great Career and a Great Life!!

Prepare but don't stress!!

Hello All,

This post is for NET aspirants who are appearing in exam on July 10, 2016. Here I am giving some tips to those candidates who are running against time to prepare their best for this Sunday exam.

Tip #1.
Now you have less than 2 days to prepare, focus on only revision of already prepared topics. For this, solve only MCQs from various resources. Don't start reading any new topic. It is better to revise to the heart the concepts you can understand and can devote some more minutes to feel confident. Staring anything new will not help and on the contrary, will make you nervous if you find the topic difficult to understand. What will be the result? You will feel less confident. Staying confident plays a vital role in your final day performance. If you are confident you may even make a good guess for a question you didn't understand well. However, if you are nervous, you are bound to make silly mistakes like shading the wrong oval of the question you knew the answer (this is my personal experience :-)) or thinking too hard on a simple question.

Tip #2.
If you feel you are not well prepared, don't get any stress. Just do as told in first tip, revise only. Getting stress never helps. It drains your energy and affects your concentration levels. Stay relaxed. If you are lucky, you may get most of the questions from your prepared topics. If not, then give yourself 6 more months to prepare and prepare better. There is no limit on no. of attempts.

Tip #3.
Don't lose your sleep because you could not study well in last few days or weeks due to some personal or family problems (or due to any other reason). If you think you can cover up for the lost time by sleeping less or by studying more than your body allows you then sorry. Studying more than you can will actually exhaust you. NET preparation is not a one-day wonder. It takes planning and patience (I have talked a lot about it my previous posts). Give yourself another shot (Come next exam!)

In this post, I do not mean to underestimate the value of hard work and never want you to postpone your success. I simply want to stress on the fact that getting stressed will not help. It is human tendency to go slow in the beginning and going haste in the last hours. Get out of this habit and make a schedule and plan for clearing the NET exam and devote good time daily for 5-6 months to study.
Daily watering of plants in moderate amount is better than throwing bucketful water once a week. Similarly, relaxed daily study is better than overly stretched study for a few days only.

Best of luck!!

DBMS Notes Series-1: Tricky Questions from Previous Papers

Hello Friends!

Let's discuss questions on DBMS from previous year papers. To begin with, some of the multiple choice type questions are listed below:

Q. Location transparency allows :
 I. Users to treat the data as if it is done at one location.
 II. Programmers to treat the data as if it is at one location.
 III. Managers to treat the data as if it is at one location.
 Which one of the following is correct ?
 (A) I, II and III (B) I and II only (C) II and III only (D) II only

The right answer is (A). 
Reason: Location transparency means the location of data must not matter to the person who accesses/manipulates the data. This is a feature of distributed databases, which applies to every kind of database user. According to a definition on Wikipedia, "The location of a resource doesn't matter to either the software developers or the end-users. This creates the illusion that the entire system is located in a single computer, which greatly simplifies software development."

The I and II are database users. The III is a component of distributed databases. Database Manager components are responsible for providing seamless data access to users without regards to its location. Hence, this covers all 3 choices.

Q. Which of the following is correct?
I. Two phase locking is an optimistic protocol.
II. Two phase locking is pessimistic protocol
III. Time stamping is an optimistic protocol.
IV. Time stamping is pessimistic protocol.

(A) I and III (B) II and IV (C) I and IV (D) II and III

The right answer is (D).
Reason: Optimistic Vs. Pessimistic approach: The optimistic concurrency control approach doesn't actually lock anything. It is based on the assumption that conflicts of database operations are very less. Means, when when oner transaction is executing, other transactions will not access the same data item being accessed by the executing one. It lets transactions run to completion and only checks for conflicts when they are about to commit. Thus, a transaction is executed without any restrictions until it is committed.

The pessimistic approach believes that some other transaction might try to access the same piece of data. So, in order to prevent any conflict, a transaction will first acquire all the required locks, then perform all the operations. It has two phases:
1. Growing Phase, where a transaction must first acquire all the locks.
2. Shrinking Phase, where a transaction releases all the locks one-by-one.(It cannot issue lock requests here.)

Q. Data warehousing refers to
(A) storing data offline at a separate site (B) backing up data regularly
(C) is related to data mining (D) uses tape as opposed to disk

The right answer is (C)

Reason: NOT A because: Not all data of Data warehouse stored offline as it depends on nature and usage of data.

NOT B because: A data warehouse typically stores a lot of historical data, that is often not subject to change. Data that does not change only needs to be backed up once.

NOT D because: Data may be stored using a proper mix of disks, tapes, or near-line storage.

Common data warehouse models include a data warehouse that is subject oriented, time variant, non-volatile, and integrated.

Q. The "PROJECT' operator of a relational algebra creates a new table that has always

(A) More columns than columns in original table

(B) More rows than original table

(C) Same number of rows as the original table

(D) Same number of columns as the original table

The right answer is (A) 

Reason: The number of tuples in the result of PROJECT  <list> (R) is always less or equal to the number of tuples in R.

Now, a few questions with descriptive answers:

Q. Show that 2-phase locking ensures serializability?

A. In databases and transaction processing two-phase locking, (2PL) is a concurrency control method that guarantees serializability. A transaction is said to follow the two-phase locking protocol if all locking operations (read_lock, write_lock) precede the first unlock operation in the transaction. Such a transaction can be divided into two phases:

Phase 1: Growing Phase
i)  transaction may obtain locks
ii)  transaction may not release locks

Phase 2: Shrinking Phase
i)  transaction may release locks
ii)  transaction may not obtain locks

If lock conversion is allowed, then upgrading of locks (from read-locked to write-locked) must be done during the expanding phase, and downgrading of locks (from write-locked to read-locked) must be done in the shrinking phase. Hence, a read_lock(X) operation that downgrades an already held write lock on X can appear only in the shrinking phase.

The protocol assures serializability. It can be proved that the transactions can be serialized in the order of their lock points  (i.e. the point where a transaction acquired its final lock). Two-phase locking does not ensure freedom from deadlocks.

Q. How to determine candidate key(s) for a relation?

A. Finding candidate keys is just as simple as applying some algorithm here and there.
In the first example, there are five attributes:
W H O S E
WH -> S
HOS -> E
Steps:
1. Find the attributes that are neither on the left and right side
> (none)
2. Find attributes that are only on the right side
> E
3. Find attributes that are only on the left side
> WHO
4. Combine the attributes on step 1 and 3
> since step 1 has no attributes, it’s just WHO
5. Test if the closures of attributes on step 4 are all the attributes
> in this case, it is true. Because with WH we can get S, and by HOS, we can get E.
So we have only one candidate key that is WHO.

Q. What are steps of a Database design?

A. Major Steps in Database Design are:

1. Requirements Analysis: Talk to the potential users! Understand what data is to be stored, and what operations and requirements are desired.
2. Conceptual Database Design: Develop a high-level description of the data and constraints (we will use the ER data model)
3. Logical Database Design: Convert the conceptual model to a schema in the chosen data model of the DBMS. For a relational database, this means converting the conceptual to a relational schema (logical schema).
4. Schema Refinement: Look for potential problems in the original choice of schema and try to redesign.
5. Physical Database Design: Direct the DBMS into choice of underlying data layout (e.g., indexes and clustering) in hopes of optimizing the performance.
6. Applications and Security Design: It defines how the underlying database will interact with surrounding applications.

Q. Differentiate b/w Specialisation and Generalisation in ER Model?

A. Specialisation:
Top-down design process; we designate subgroupings within an entity set that are distinctive from other entities in the set.
These subgroupings become lower-level entity sets that have attributes or participate in relationships that do not apply to the higher-level entity set.
Depicted by a triangle component labeled ISA (E.g. customer “is a” person).
Attribute inheritance – a lower-level entity set inherits all the attributes and relationship participation of the higher-level entity set to which it is linked.

Generalisation:
A bottom-up design process – combine a number of entity sets that share the same features into a higher-level entity set.
Specialization and generalization are simple inversions of each other; they are represented in an E-R diagram in the same way.
The terms specialization and generalization are used interchangeably.

Cracking NET: No Instant Recipe but Strategy

Dear Friends!

I have been sharing my views on strategy for succeeding in NET exam on this blog as well as in Facebook groups. Most of times, I am thrown the queries on "Instant Recipe" for success in NET....like:

"Do you have study material for NET exam?"

"How I can prepare in next 2-3 months so that I crack the next exam?"

I start wondering why people look for "Instant Formula" to get success in competitive exams like UGC NET? Perhaps the "successful" formulas used by them in academic exams of their degree made them to think the same way for UGC NET exam also, but sorry, it is not that easy.

Before the pattern of NET examination was changed to 100% objective, Paper-III was subjective. You were supposed to secure just passing marks (40%) in paper III and 50% in total of Paper I and Paper II. It means, there was no criteria of falling in top 15% of eligible candidates. Still, the rate of success in Computer Science was dismally low all over India.

Now, the pattern has been changed and the high ratio of successful candidates is an indicator that cracking NET is far easier now. But, still, there is no "Instant Recipe" for success in NET.

NET preparation takes planning as well as patience. Unless you are born genius and covered all important topics of NET exam with utmost sincerity as a student and started preparing while you were in 1st semester of Masters degree....it definitely takes time to qualify. How much of time? It all depends on 3 factors, which we will discuss at the end.

Previously I posted two articles: One-> Getting success in NET exam, Two-> Securing great marks. In this post, I am sharing some more ideas on planning for your goal to qualify the Exam. Your success depends much on the dedicated execution of these steps.

First:

Select the topics you can study and prepare well for the next NET exam. You better focus on only those subjects you know are important to cover and also, you are confident that you can understand and can study them in short time. One strategy to choose the topics is to select 7-8 old topics, means, the topics you have already studied in your Masters. Additionally, select one or two new topics which you have never studied but are important for NET exam. For example, I had never heard about Theory of Computation (TOC) while doing MCA. The questions from this subject are always asked in paper II and/or paper III. You will need to select around 10 subjects.
For your old subjects, make a list of books you need to study. Follow the standard and famous books.

For the new topics, it would be better either you watch tutorial videos on NPTEL website, Youtube or find a good book for beginners on such topic. In my case, to learn Automata, I started with the book by Ullman. But that was a mistake, since the language of this book is not suitable for beginners. So, I shifted to online Videos and other web-based tutorials.  I later came to know that books on Automata by Peter Linz and Mishra were better for beginners.

For now, in first step, Do not start reading/re-reading books. Do this after following the next step.

Second:

Now, download all previous UGC papers from cbsenet.nic.in as well as ugcnetonline.in. For saving your time, here are the URLs to old question papers:

1. December 2015
2. June 2015

3. December 2014

4. June 2009 to June 2014

Now take printout of all the papers if you prefer to study offline. In my case, I took printout of all question papers and binded all papers in order like an MCQ book. Study the questions of all 3 papers. Try to understand the pattern and the types of questions asked. (Right now, do not focus on solutions to the problems, just develop an understanding on the types of the questions). 

To do this exercise in a planned manner, select any one topic and study questions from that topic only - in all question papers. For example, if you choose to begin with OS, make a list of only OS related questions from previous papers. On average, you will find 5-6 questions on OS from each exam session. It means, you will have more than 60 questions in hand on OS. If you have just began to prepare for NET, it is for sure that you will find that more than 50% questions are challenging. Highlight such questions. Do the same for all other topics. (Right now, we are not focusing on the solutions to the questions, but simply developing understanding of the topics). Solve  the questions as mentioned in third step.

Third:

Now solve the questions (which you selected in previous step) in three ways:

1. Find the topics in the text book, for example Galvin, and read the text. Make notes of important concepts. If you are short of time, simply use highlighter to mark in the book itself (Don't do this in borrowed books :-)

2. If  you could not find useful information in the book, take help of Google to research these questions. You will find Tens of useful links to study.

3. Still, if you fail to find the solution, post your question if forums like Facebook groups you have joined, online blogs related to your topic etc. Someone will definitely post answer to your question in any of the forums.

Remember, solving each challenging question can take time. Sometimes, it may take even 2 hours just to find the right answer and concept behind the asked question. (DO NOT CRAM ANS KEYS GIVEN BY UGC. I too made this mistake. It consumes time but is least helpful.) Why I have asked to do this step? You are not supposed to remember the given answers, but study the concept behind each such question. If you get the concept right, you will find many other questions easy to answer which are based on the same concept. If later you read the same questions or other questions on the concept you learnt, you will realise that you can now understand the problem in a better manner before you covered the topics.

Fourth:

After covering most of previous NET questions, research more on MCQ from other resources (both offline and online). Start solving questions from MCQ book by authors like Timothy Williams and any other you consider as good book. 

You may also use web sites some of which I am listing below:

http://www.geeksforgeeks.org/

http://nptel.ac.in/course.php

http://www.indiabix.com/engineering/

Last thing! There are three factors which will decide the direction of your exam preparation:
#1. (Most Important) Your focus on your goal (means how much serious you are to crack the NET)

#2. Your previous academics, means how much and which subjects you have learnt good by the time you complete your masters.

#3. Your perseverance, means "Never Say Die" spirit even if it is taking longer than you thought to qualify the exam. I stressed on this attitude in one of my previous posts also.

These 3 factors will decide when and how you will succeed.

Readers! The only objective of this post is to make you realise that it is better to equip yourself with all necessary Armour for hitting the exam. Give yourself at least 6 months of dedicated preparation. After 6 months, you will be confident on the concepts as well as on how to solve MCQs.

Best of Luck for July 2016 exam!