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Archive for the ‘SQL Puzzle’ Category

SQL SERVER – Expanding Views – Contest Win Joes 2 Pros Combo (USD 198) – Day 4 of 5

Posted in Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology on August 9, 2012 | 17 Comments »

August 2011 we ran a contest where every day we give away one book for an entire month. The contest had extreme success. Lots of people participated and lots of give away. I have received lots of questions if we are doing something similar this month. Absolutely, instead of running a contest a month long we are doing something more interesting. We are giving away USD 198 worth gift every day for this week. We are giving away Joes 2 Pros 5 Volumes (BOOK) SQL 2008 Development Certification Training Kit every day. One copy in India and One in USA. Total 2 of the giveaway (worth USD 198). All the gifts are sponsored from the Koenig Training Solution and Joes 2 Pros.

The books are available here Amazon | Flipkart 

How to Win:

  • Read the Question
  • Read the Hints
  • Answer the Quiz in Contact Form in following format
    • Question
    • Answer
    • Name of the country (The contest is open for USA and India residents only)
  • 2 Winners will be randomly selected announced on August 20th.

Question of the Day:

Which of the following key word will force the query to use indexes created on views?

a) ENCRYPTION
b) SCHEMABINDING
c) NOEXPAND
d) CHECK OPTION

Query Hints:

BIG HINT POST

Usually, the assumption is that Index on the table will use Index on the table and Index on view will be used by view. However, that is the misconception. It does not happen this way. In fact, if you notice the image, you will find the both of them (table and view) use both the index created on the table. The index created on the view is not used. The reason for the same as listed in BOL.

The cost of using the indexed view may exceed the cost of getting the data from the base tables, or the query is so simple that a query against the base tables is fast and easy to find. This often happens when the indexed view is defined on small tables. You can use the NOEXPAND hint if you want to force the query processor to use the indexed view. This may require you to rewrite your query if you don’t initially reference the view explicitly. You can get the actual cost of the query with NOEXPAND and compare it to the actual cost of the query plan that doesn’t reference the view. If they are close, this may give you the confidence that the decision of whether or not to use the indexed view doesn’t matter.

Additional Hints:

I have previously discussed various concepts from SQL Server Joes 2 Pros Volume 4.

Next Step:

Answer the Quiz in Contact Form in following format

  • Question
  • Answer
  • Name of the country (The contest is open for USA and India)

Bonus Winner

Leave a comment with your favorite article from the “additional hints” section and you may be eligible for surprise gift. There is no country restriction for this Bonus Contest. Do mention why you liked it any particular blog post and I will announce the winner of the same along with the main contest.

Reference: Pinal Dave (http://blog.sqlauthority.com)

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SQL SERVER – Clustered Index and Primary Key – Contest Win Joes 2 Pros Combo (USD 198) – Day 3 of 5

Posted in Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology on August 8, 2012 | 22 Comments »

August 2011 we ran a contest where every day we give away one book for an entire month. The contest had extreme success. Lots of people participated and lots of give away. I have received lots of questions if we are doing something similar this month. Absolutely, instead of running a contest a month long we are doing something more interesting. We are giving away USD 198 worth gift every day for this week. We are giving away Joes 2 Pros 5 Volumes (BOOK) SQL 2008 Development Certification Training Kit every day. One copy in India and One in USA. Total 2 of the giveaway (worth USD 198). All the gifts are sponsored from the Koenig Training Solution and Joes 2 Pros.

The books are available here Amazon | Flipkart 

How to Win:

  • Read the Question
  • Read the Hints
  • Answer the Quiz in Contact Form in following format
    • Question
    • Answer
    • Name of the country (The contest is open for USA and India residents only)
  • 2 Winners will be randomly selected announced on August 20th.

Question of the Day:

Which of the following datatype is usually NOT the best choice for Primary Key and Clustered Index?

a) INT
b) BIGINT
c) GUID
d) SMALLINT

Query Hints:

BIG HINT POST

The clustered index is the placement order of a table’s records in memory pages. When you insert new records, then each record will be inserted into the memory page in the order it belongs. In the figure below we see another new record (Major Disarray) being inserted, in sequence, between Jonny and Rick. Since there is no room in this memory page, some records will need to shift around. The page split occurs when Irenes’ record moves to the second page. Page splits are considered very bad for performance, and there are a number of techniques to reduce, or even eliminate, the risk of page splits.

You can create a clustered index on the table on any field you choose. Sometime SQL will create a clustered index for you. Often times the field having the Primary Key makes a great candidate for the clustered index.

Additional Hints:

I have previously discussed various concepts from SQL Server Joes 2 Pros Volume 3.

Next Step:

Answer the Quiz in Contact Form in following format

  • Question
  • Answer
  • Name of the country (The contest is open for USA and India)

Bonus Winner

Leave a comment with your favorite article from the “additional hints” section and you may be eligible for surprise gift. There is no country restriction for this Bonus Contest. Do mention why you liked it any particular blog post and I will announce the winner of the same along with the main contest.

Reference: Pinal Dave (http://blog.sqlauthority.com)

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SQL SERVER – Identity Fields – Contest Win Joes 2 Pros Combo (USD 198) – Day 2 of 5

Posted in Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology on August 7, 2012 | 18 Comments »

August 2011 we ran a contest where every day we give away one book for an entire month. The contest had extreme success. Lots of people participated and lots of give away. I have received lots of questions if we are doing something similar this month. Absolutely, instead of running a contest a month long we are doing something more interesting. We are giving away USD 198 worth gift every day for this week. We are giving away Joes 2 Pros 5 Volumes (BOOK) SQL 2008 Development Certification Training Kit every day. One copy in India and One in USA. Total 2 of the giveaway (worth USD 198). All the gifts are sponsored from the Koenig Training Solution and Joes 2 Pros.

The books are available here Amazon | Flipkart 

How to Win:

  • Read the Question
  • Read the Hints
  • Answer the Quiz in Contact Form in following format
    • Question
    • Answer
    • Name of the country (The contest is open for USA and India residents only)
  • 2 Winners will be randomly selected announced on August 20th.

Question of the Day:

Which of the following statement is incorrect?

a) Identity value can be negative.
b) Identity value can have negative interval.
c) Identity value can be of datatype VARCHAR
d) Identity value can have increment interval larger than 1

Query Hints:

BIG HINT POST

A simple way to determine if a table contains an identity field is to use the SSMS Object Explorer Design Interface. Navigate to the table, then right-click it and choose Design from the pop-up window. When your design tab opens, select the first field in the table to view its list of properties in the lower pane of the tab (In this case the field is ProductID). Look to see if the Identity Specification property in the lower pane is set to either yes or no. SQL Server will allow you to utilize IDENTITY_INSERT with just one table at a time. After you’ve completed the needed work, it’s very important to reset the IDENTITY_INSERT back to OFF.

Additional Hints:

I have previously discussed various concepts from SQL Server Joes 2 Pros Volume 2.

Next Step:

Answer the Quiz in Contact Form in following format

  • Question
  • Answer
  • Name of the country (The contest is open for USA and India)

Bonus Winner

Leave a comment with your favorite article from the “additional hints” section and you may be eligible for surprise gift. There is no country restriction for this Bonus Contest. Do mention why you liked it any particular blog post and I will announce the winner of the same along with the main contest.

Reference: Pinal Dave (http://blog.sqlauthority.com)

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SQL SERVER – Query Hint – Contest Win Joes 2 Pros Combo (USD 198) – Day 1 of 5

Posted in Joes 2 Pros, PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology on August 6, 2012 | 22 Comments »

August 2011 we ran a contest where every day we give away one book for an entire month. The contest had extreme success. Lots of people participated and lots of give away. I have received lots of questions if we are doing something similar this month. Absolutely, instead of running a contest a month long we are doing something more interesting. We are giving away USD 198 worth gift every day for this week. We are giving away Joes 2 Pros 5 Volumes (BOOK) SQL 2008 Development Certification Training Kit every day. One copy in India and One in USA. Total 2 of the giveaway (worth USD 198). All the gifts are sponsored from the Koenig Training Solution and Joes 2 Pros.

The books are available here Amazon | Flipkart 

How to Win:

  • Read the Question
  • Read the Hints
  • Answer the Quiz in Contact Form in following format
    • Question
    • Answer
    • Name of the country (The contest is open for USA and India residents only)
  • 2 Winners will be randomly selected announced on August 20th.

Question of the Day:

Which of the following queries will return dirty data?

a) SELECT * FROM Table1 (READUNCOMMITED)
b) SELECT * FROM Table1 (NOLOCK)
c) SELECT * FROM Table1 (DIRTYREAD)
d) SELECT * FROM Table1 (MYLOCK)

Query Hints:

BIG HINT POST

Most SQL people know what a “Dirty Record” is. You might also call that an “Intermediate record”. In case this is new to you here is a very quick explanation. The simplest way to describe the steps of a transaction is to use an example of updating an existing record into a table. When the insert runs, SQL Server gets the data from storage, such as a hard drive, and loads it into memory and your CPU. The data in memory is changed and then saved to the storage device. Finally, a message is sent confirming the rows that were affected.

For a very short period of time the update takes the data and puts it into memory (an intermediate state), not a permanent state. For every data change to a table there is a brief moment where the change is made in the intermediate state, but is not committed. During this time, any other DML statement needing that data waits until the lock is released. This is a safety feature so that SQL Server evaluates only official data.

For every data change to a table there is a brief moment where the change is made in this intermediate state, but is not committed. During this time, any other DML statement (SELECT, INSERT, DELETE, UPDATE) needing that data must wait until the lock is released. This is a safety feature put in place so that SQL Server evaluates only official data.

Additional Hints:

I have previously discussed various concepts from SQL Server Joes 2 Pros Volume 1.

Next Step:

Answer the Quiz in Contact Form in following format

  • Question
  • Answer
  • Name of the country (The contest is open for USA and India)

Bonus Winner

Leave a comment with your favorite article from the “additional hints” section and you may be eligible for surprise gift. There is no country restriction for this Bonus Contest. Do mention why you liked it any particular blog post and I will announce the winner of the same along with the main contest.

Reference: Pinal Dave (http://blog.sqlauthority.com)

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SQL SERVER – Monday Morning Puzzle – Query Returns Results Sometimes but Not Always

Posted in PostADay, SQL, SQL Authority, SQL Interview Questions and Answers, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology on July 9, 2012 | 14 Comments »

The amount of email I receive sometime it is impossible for me to answer every email. Nonetheless I try to answer pretty much every email I receive. However, quite often I receive such questions in email that I have no answer to them because either emails are not complete or they are out of my domain expertise. In recent times I received one email which had only one or two lines but indeed attracted my attention to it. The question was bit vague but it indeed made me think. The answer was not straightforward so I had to keep on writing the answer as I remember it. However, after writing the answer I do not feel satisfied. Let me put this question in front of you and see if we all can come up with a comprehensive answer.

Question: I am beginner with SQL Server. I have one query, it sometime returns a result and sometime it does not return me the result. Where should I start looking for a solution and what kind of information I should send to you so you can help me with solving. I have no clue, please guide me.

Well, if you read the question, it is indeed incomplete and it does not contain much of the information at all. I decided to help him and here is the answer, which I started to compose.

Answer: As there are not much information in the original question, I am not confident what will solve your problem. However, here are the few things which you can try to look at and see if that solves your problem.

  • Check parameter which is passed to the query. Is the parameter changing at various executions?
  • Check connection string – is there some kind of logic around it?
  • Do you have a non-deterministic component in your query logic? (In other words – does your result is based on current date time or any other time based function?)
  • Are you facing time out while running your query?
  • Is there any error in error log?
  • What is the business logic in your query?
  • Do you have all the valid permissions to all the objects used in the query? Are permissions changing or query accessing a different object in various executions?
  • (Add your suggestions here)

Meanwhile, have you ever faced this situation? If yes, do share your experience in the comment area. I will send a copy of my book SQL Server Interview Questions and Answers to one of the most interesting comment. The winner will be announced by next Monday. 

Reference: Pinal Dave (http://blog.sqlauthority.com)

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