In our DB world ,the most scary term we heard is performance issues. Most of the effective investigation mostly point  to no-usage or wrong usage of Indexes.I have  been working or learning  with a lot of good Data Gurus for a time now #SSGeeks.I surfed around the sea of unlimited knowledge available in the blog of DB professionals like me and jot down some important facts about Indexes 

The Index Breakdown Basics.

An index is an object in a database.

All items within a database are objects.

An indexes job is to speed up data retrieval for queries.

The are various kind of indexes but most of the time in OLTP environments we are taking about two.

The clustered index and the non-clustered index.

The clustered index is the data.

A non-clustered index is a separate object and it’s used to speed up data retrieval.

Most transactions in an OLTP environment fall into 4 categories when an application is in use.

Data is retrieved.

Data is updated.

Data is inserted.

Data is deleted.

Hopefully, most OLTP boxes will be heavy on insets and selects. (the select is how we retrieve data)

Indexes aren’t free. They take up space and we are penalized when data is inserted. (more reasons but that’s another story)

That’s because every non-clustered index points back to the clustered index and has to be updated.

If you have a table that’s heavily inserted into, the more indexes… the wider the index… the slower the performance of those inserts.

The goal of every OLTP app is balance.

You need the right combination of indexes to speed up data retrieval yet limit them so they don’t degrade performance on inserts.

That doesn’t sound so difficult so what’s the issue?

You are building an application and there are 10 developers adding indexes to their code on the same tables. Imagine the overlap on those tables.

Most companies put more than one database on each production instance.

These databases complete for the same critical resources. (mem, I/O, CPU)

If you have 10 databases on an instance and those 10 databases have 100 indexes and half of them are junk then the entire box is being affected by poor indexing.

The goal of performance tuning is two fold.

Number one, speed up queries for data retrieval.

Secondly, reduce resource consumption across the board on that box.

So, it  is  always good to remove the unnecessary indexes (especially those with the largest insert penalty) and to create the most impacting  indexes at the *INSTANCE* level.

If you wanna add something related to the post please feel free to ping it in comments section .  Mainly it is all about our ♥  for  Databases.

Signing off.

@DB#untuned

Tune...tune hai mujhe banaya

Dedicated to my mom,sisters,friends,teachers,mentor, colleagues , to whom we have to Thank for so many and so different reasons but the most important being; our sheer existence.

Tujhse mila jo pehli baar
ladkarate mere kadm ko sambhal ,
tune mujhe chalna sikhaya
Aur bhej fir duniya k beech
Mushkilo se ladna sikhaya,
Ayee jab naa raato ko neeend
Kisso se mera man behlaya
Galtiyo se pitne se
nazaaane kitni bar bachaya,
Jab bhi pari zaroorat
thamne mera haath
tune hi apna haath badaya
teri har cheez par maine
hamesha apna haq jataya,
tujhse kuch bhi kehte
main kabhi naaa sharmaya
Par aksar bin kahe hi
tujhe sab samajh mein aaya,
Iss baar mila jab tujhse
tune ek hassen kkhwab dikhaya
jisko paane ki koshish mein
Mujhko kuch behter banaya
 Badli zindegi fir ek baar
jabse isme tu aaya
Apne payar se tune mujhko
hai jine ka dhang sikhlaya
ho gaya pura main
jab tune haas kar gale lagaya


kabhi hasaya ,kabhi rulaya
Tujhse maine sab kuch paya
har pehlu mein zindegi ki meri
tera hi hai aks samaya

Tune...tune hai mujhe banaya

Acceptance testing

As now a days my I have nothing good to do with my time ,I came up with an idea ie to read other peoples blog mainly of technical topics{Other than visiting social sites } since I am switching streams I found it quite informative since I am a novice to this industry.As today I was going through the blog of my cousin brother whom I used to consider a geek during his engineering college days...I found out an interesting  topic about  UAT..Naturally to know the  full-form I hit the Google  bar and came up with its full form User Acceptance Testing (UAT)..by virtue of my curiousness I moved deeper
  
I started my search on it and I found out it to be more interesting than I thought it would be..actually UAT is a form of acceptance testing that generally done in every field be it aviation of chemical only the name changes the concept remains the same..In engineering and its various sub disciplines, acceptance testing is a test conducted to determine if the requirements of a specification or contract are met. It may involve chemical tests, physical tests, or performance tests.in a flow chart 

Types of Acceptance tests 
 Typical types of acceptance testing include the following

User acceptance testing (UAT)

This may include factory acceptance testing, i.e. the testing done by factory users before the factory is moved to its own site, after which site acceptance testing may be performed by the users at the site.

Operational Acceptance Testing (OAT)

Also known as operational readiness testing, this refers to the checking done to a system to ensure that processes and procedures are in place to allow the system to be used and maintained. This may include checks done to back-up facilities, procedures for disaster recovery, training for end users, maintenance procedures, and security procedures.

Contract and regulation acceptance testing

In contract acceptance testing, a system is tested against acceptance criteria as documented in a contract, before the system is accepted. In regulation acceptance testing, a system is tested to ensure it meets governmental, legal and safety standards. Here one of the aviation tests in the picture 

Alpha and beta testing

Alpha testing takes place at developers' sites, and involves testing of the operational system by internal staff, before it is released to external customers. Beta testing takes place at customers' sites, and involves testing by a group of customers who use the system at their own locations and provide feedback, before the system is released to other customers. The latter is often called “field testing”.

Now with all that knowledge I hope I need to dig dwn dip to know more about UAT as its is considered a vital stage of  the project before handed over to the clients re it is .Hope to come back with more info on that in near future 

[edit]

Too good replies.. Must Read

These are some random questions supposedly asked at the top level exams with  very witty answers. So read On…

Q. How can you drop a raw egg onto a concrete floor without cracking it?
A. Concrete floors are very hard to crack! 

Q.If it took eight men ten hours to build a wall, how long would it take
four men to build it?
A. No time at all it is already built. 

Q.If you had three apples and four oranges in one hand and four apples and
three oranges in the other hand, what would you have?
A. Very large hands.(Good one)

Q. How can you lift an elephant with one hand?
A. It is not a problem, since you will never find! An elephant with one
hand.

Q. How can a
man go eight days without sleep?
A. No Probs , He sleeps at night. 

Q. If you throw a red stone into the blue sea what it will become?
A. It will Wet or Sink as simple as that. 

Q. What looks like half apple ?
A : The other half.

Q. What can you never eat for breakfast?
A : Dinner.

Q. What happened when wheel was invented ?
A : It caused a revolution.

Q. Bay of Bengal is in which state?
A : Liquid

Interviewer said “I shall either ask you ten easy questions or one really difficult question”, think well before you make up your mind!

The boy thought for a while and
said, “my choice is one really difficult question.”

Well, good luck to you, you have made your own choice! Now tell me this;

“What comes first, Day or Night?”

The boy was jolted into reality as his admission depends on the correctness of his answer, but he thought for a while and said, “It’s the DAY sir!”

“How?”, the interviewer asked,

“Sorry sir, you promised me that you will not ask me a SECOND difficult question!”

He was selected for IIM!

“Technical Skill is the mastery of complexity, while Creativity is the master of presence of mind”

BEING IN TWENTIES – SOMETHING

I considered this mail as just another forward till i read it. Worth a read atleast once.. What do u say ??

It is when you stop going along with the crowd and start realizing that there are many things about yourself that you didn’t know and may not like. You start feeling insecure and wonder where you will be in a year or two, but then get scared because you barely know where you are now.

You start realizing that people are selfish and that, maybe, those friends that you thought you were so close to aren’t exactly the greatest people you have ever met, and the people you have lost touch with are some of the most important ones. What you don’t recognize is that they are realizing that too, and aren’t really cold, catty, mean or insincere, but that they are as confused as you.

You look at your job… and it is not even close to what you thought you would be doing, or maybe you are looking for a job and realizing that you are going to have to start at the bottom and that scares you.

Your opinions have gotten stronger. You see what others are doing and find yourself judging more than usual because suddenly you realize that you have certain boundaries in your life and are constantly adding things to your list of what is acceptable and what isn’t. One minute, you are insecure and then the next, secure.

You laugh and cry with the greatest force of your life. You feel alone and scared and confused. Suddenly, change is the enemy and you try and cling on to the past with dear life, but soon realize that the past is drifting further and further away, and there is nothing to do but stay where you are or move forward.

You get your heart broken and wonder how someone you loved could do such damage to you. Or you lie in bed and wonder why you can’t meet anyone decent enough that you want to get to know better. Or maybe you love someone but love someone else too and cannot figure out why you’re doing this because you know that you aren’t a bad person. One night stands and random hook ups start to look cheap. Getting wasted and acting like an idiot starts to look pathetic. You go through the same emotions and questions over and over, and talk with your friends about the same topics because you cannot seem to make a decision. You worry about loans, money, the future and making a life for yourself… and while winning the race would be great, right now you’d just like to be a contender!

What you may not realize is that every one reading this relates to it. We are in our best of times and our worst of times, trying as hard as we can to figure this whole thing out.

We call it the “Quarter-life Crisis.

Walking in the rain

Oh Mister Weather man
Where's that rain you promised me
Oh Mister Weather man
I've been waiting patiently
Mister can you spare a drop
Here a drop, there a drop
Two drops, four drops
Can't we have more drops
Now its all around me
Gee I'm glad you found me
Well, I'm listening to the pitter-patter of the rain
Alone in the middle of my way..
My ol'heart begins to feel the pain..
Of missing you with all my might..
But your not here to share my love..
So I'll just face this pain alone...
And listen to the rain falling from above
And face the fact that you are gone,
Rain falling from above...
Rain falling for my love...
Rain falling from the skies...
And rain falling from my eyes..
So I'm listening to the pitter-patter of the rain
And listening to how sad it sounds....

Some Important Facts and Informations....................

01. A cat has 32 muscles in each ear.

02. A crocodile cannot stick out its tongue.

03. A dragonfly has a life span of 24 hours.

04. A goldfish has a memory span of three seconds.

05. A “jiffy” is an actual unit of time for 1/100th of a second.

06. A shark is the only fish that can blink with both eyes.

07. A snail can sleep for three years.

08. Al Capone’s business card said he was a used furniture dealer.

09. All 50 states are listed across the top of the Lincoln Memorial on the back of the $5 bill.

10.  Almonds are a member of the peach family.

11. An ostrich’s eye is bigger than its brain.

12. Babies are born without kneecaps.

13. They don’t appear until the child reaches 2 to 6 years of age.

14. Butterflies taste with their feet.

15. Cats have over one hundred vocal sounds. Dogs only have about Ten.

16. “Dreamt” is the only English word that ends in the letters “MT”.

17. February 1865 is the only month in recorded history not to have a full moon.

18. In the last 4,000 years, no new animals have been domesticated.

19. If the population of China walked past you, in single file, the line would never end because of the rate of reproduction.

20. If you are an average American, in your whole life, you will spend an average of 6 months waiting at red lights.

21.It’s impossible to sneeze with your eyes open.

22. Maine is the only state whose name is just one syllable.

23. Our eyes are always the same size from birth, but our nose and ears never stop growing.

24. A dime has 118 ridges around the edge.

25.Peanuts are one of the ingredients of dynamite.

26.  Rubber bands last longer when refrigerated.

27. “Stewardesses” is the longest word typed with only the left hand and “lollipop” with your right.

28. The average person’s left hand does 56% of the typing.

29. The cruise liner, QE2, moves only six inches for each gallon of die! Sel that it burns.

30. The microwave was invented after a researcher walked by a radar tube and a chocolate bar melted in his pocket.

31. The sentence: “The quick brown fox jumps over the l! Azy dog” uses every letter of the alphabet.

32. The winter of 1932 was so cold that Niagara Falls froze completely solid.

33. The words ‘racecar,’ ‘kayak’ and ‘level’ are the same whether they are read left to right or right to left (palindromes).

34. There are 293 ways to make change for a dollar.

35. There are more chickens than people in the world.

36. There are only four words in the English language which end in “dous”: tremendous, horrendous, stupendous, and hazardous

37. There are two words in the English language that have all five vowels in order: “abstemious” and “facetious.”

38. There’s no Betty Rubble in the Flintstones Chewables Vitamins.

39. Tigers have striped skin, not just striped fur.

40. TYPEWRITER is the longest word that can be made using the letters only on one row of the keyboard.

41. Winston Churchill was born in a ladies’ room during a dance.

42. Women blink nearly twice as much as men.

43. Your stomach has to produce a new layer of mucus every two weeks; otherwise it will digest itself