Question 70-229
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Hi,
I am preparing for exam 70-229 and now learning transactions and locks.
It is a bit difficult for me to learning locks in detail.
My question is does anyone know if it was anytime a question about locks at 70-229?
Daniela
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Daniela,
You do have to know locks. 3 cases out of 4 when users call me complaining they can not access databases deal with locking problems. You have to know why does it happen, how to identify there is a locking issue, what are exclusive locks etc. Also, since 70-229 is a development exam you have to know how to design the database to avoid locking issues. I am talking not from the point of view of the exam but from the point of view of the practical DBA.
You don't need to remember details. You need to read and understand. Once you understand the concept you will be able to answer exam questions.
Regards,Yelena Varsha
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Yes, transaction and lock questions will be on the 70-229 test. Here's Microsoft's list of the topics to be prepared for:
http://www.microsoft.com/learning/exams/70-229.asp
Also, check out the free Cramsession study guide:
http://www.cramsession.com/certifications/exams/sql-2000-design.asp
(click the ad to download the free study guide)
Although it has been a couple years since I took the test, I remember there were questions like:
Start with x and y equal to zero.
BEGIN TRANSACTION
Update table1
set x=1
COMMIT TRANSACTION
BEGIN TRANSACTION
Update table2
set y=2
ROLLBACK TRANSACTION
Question: What are the values of x and y after this has run?
Of course the Microsoft scenarios are much more complicated than this, but you get the idea. I recommend the Que book to prepare for this exam. It covers everything you need to know for the test. And of course Transcender practice exams will really measure your level of preparedness for the test. Good luck!
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The questions you'll get in the exam are selected at random from a large pool. Hence you may or may not get any questions on locks.
What's the problem you have with understanding locks?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverabilityWe walk in the dark places no others will enter
We stand on the bridge and no one may pass -
They are a lot of topics on locking at table level. I didn't work with locks (at least yet) and I am not sure which one form there is frequently used and why.I would like to concentrate on that things that is possible to use in practice, the most efficient ones
Daniela
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Understanding locking is essential if you find yourself administering a heavily-used database (or one with very bad queries and indexes)
Understanding the basics will take you a long way.
the main types of locks - IS (intent shared), S (shared), U (Update), IX (Intent Exclusive), X (Exculsive), Sch-S (Schema stability)
The levels of locking - row, page, extent, table.
The escalation of locks. Why would SQL take a page lock instead of a row lock. why it would convert several page locks to a table lock.
What locks are compatable. A shared lock won't block another shared, but will block an exclusive
What causes a deadlock?
What locking options can you set on a query. What affect does the transction isolation level have on locks?
There's a very good section in Books Online. (Accessing and Changing Relational Data->Locking)
If you want to look at locks on a server, us sp_lock. That will show you the current locks held, what objects they are held on, what spids hold those locks and what type they are. It will show you blocking. You may see lock escalation.
If you have specific questions please ask. There are a lot of very knowledgable people who frequent these forums.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverabilityWe walk in the dark places no others will enter
We stand on the bridge and no one may pass
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