October 21, 2009 at 12:47 am
Jeffrey Williams-493691 (10/20/2009)
If I am not mistaken, this issue could be avoided completely by setting up a database mirror in SQL Server 2008. SQL Server 2008 will attempt to automatically repair a corrupt page from the partner database.At least, that is what is shown here: http://www.sqlskills.com/blogs/paul/post/SQL-Server-2008-Automatic-Page-Repair-with-Database-Mirroring.aspx
GilaMonster (10/16/2009)
In 2008 with mirroring the damaged page would be automatically requested from the mirror and repaired as soon as it was found corrupt. (enterprise edition only)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
October 21, 2009 at 1:42 am
Ian Scarlett (10/20/2009)
GSquared (10/20/2009)
And you might be shocked by how many people who call themselves DBAs or who even have jobs as DBAs can't answer that question. I've met dozens.On that point we do agree.
Although, having done no end of interviewing over the years, I can't say I'm shocked any more, but I am appalled that people who claim 5+ years of experience (and even MS Certification) would get no more than 3/20 on the 20 "simple" questions we would ask at the beginning of the interview e.g.
what is the difference between a clustered/non clustered index
what is a trigger
what is referential integrity
what does truncate table do
what is the difference between simple and full recovery model etc etc.
Anybody who had 5 "real" years of experience should be getting 15+/20 easily.
lol, your first question is almost a given in any dba interview, in the ones that I have been in anyways. these are so basic questions if you didnt know them, you wouldnt even last the full interview time. The other main question that is pretty openended and is always asked is, the server is running slow, how would you troubleshoot it.
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October 21, 2009 at 7:09 am
GSquared (10/16/2009)
(I didn't get hired, with the reason given that I was "too strong on the subject", whatever that means, but it certainly made for an interesting interview.)
Ha! Translation: You'd make the boss look stupid or alternately you cost too much. :-D;-)
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"stewsterl 80804 (10/16/2009)I guess when you stop and try to understand the solution provided you not only learn, but save yourself some headaches when you need to make any slight changes."
October 21, 2009 at 7:48 am
Well, that certainly gives a good interview question to ask. We've evolved it to, "You have a database with a corrupted or lost page, and the backup chain is broken due to a lost log backup file, what do you do?" The hoped-for response is, "Is there a mirror, or a log-shipped backup, or something of that sort?"
That assumes that the person knows what a "corrupted or lost page" is, of course, which might also be a good interview question. "What are 'pages' in the context of databases?" If they can't answer that, they certainly aren't up to handling corruption issues.
- Gus "GSquared", RSVP, OODA, MAP, NMVP, FAQ, SAT, SQL, DNA, RNA, UOI, IOU, AM, PM, AD, BC, BCE, USA, UN, CF, ROFL, LOL, ETC
Property of The Thread
"Nobody knows the age of the human race, but everyone agrees it's old enough to know better." - Anon
October 21, 2009 at 8:08 am
GSquared (10/21/2009)
Well, that certainly gives a good interview question to ask. We've evolved it to, "You have a database with a corrupted or lost page, and the backup chain is broken due to a lost log backup file, what do you do?" The hoped-for response is, "Is there a mirror, or a log-shipped backup, or something of that sort?"That assumes that the person knows what a "corrupted or lost page" is, of course, which might also be a good interview question. "What are 'pages' in the context of databases?" If they can't answer that, they certainly aren't up to handling corruption issues.
Well funnily enough, I have never been asked anything like that in any interview. So I can hardly imagine it being a common question. Although my experiences might be unique 😉
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October 21, 2009 at 9:11 am
Silverfox (10/21/2009)
GSquared (10/21/2009)
Well, that certainly gives a good interview question to ask. We've evolved it to, "You have a database with a corrupted or lost page, and the backup chain is broken due to a lost log backup file, what do you do?" The hoped-for response is, "Is there a mirror, or a log-shipped backup, or something of that sort?"That assumes that the person knows what a "corrupted or lost page" is, of course, which might also be a good interview question. "What are 'pages' in the context of databases?" If they can't answer that, they certainly aren't up to handling corruption issues.
Well funnily enough, I have never been asked anything like that in any interview. So I can hardly imagine it being a common question. Although my experiences might be unique 😉
Not a common question. A good question. HUGE difference. 🙂
I've been through a lot of really ineffective questions in interviews. Ones that don't actually establish SQL competence, nor much of anything else. Some of them are pretty common. Of course, the best interview commedies are on TheDailyWTF.com. I don't have anything as good as some of those!
- Gus "GSquared", RSVP, OODA, MAP, NMVP, FAQ, SAT, SQL, DNA, RNA, UOI, IOU, AM, PM, AD, BC, BCE, USA, UN, CF, ROFL, LOL, ETC
Property of The Thread
"Nobody knows the age of the human race, but everyone agrees it's old enough to know better." - Anon
October 21, 2009 at 11:15 am
My favorite question is "How would you troubleshoot a slow running query?" and i get surprized by the replies given by the DBA candidates. They go to the extent of using SQL Profiler even without checking the query execution plan first, makes me wonder if they have ever worked on the SQL Server product to call themselves a SQL Server DBA. Another question is whats the difference between Clustered and NonClustered index and it's hard to believe that DBA candidates fail to answer this simple question.
Amol
Amol Naik
October 21, 2009 at 11:54 am
talltop-969015
You asked some simple 'baby' questions.. here they are..
*Difference between delete and truncate
*What is identity column?
*Login vs User
*What are Collations
*CAST Vs CONVERT
*Union Vs Union All
*What is ANSI
*View vs Table
*SPs Vs Functions
*What is dynamic SQL?
*SQL Vs Windows Authentication
*How do you find who are the active users in the database
*What is database fragmentation
*RAID 5 Vs 10
*What is DMV
*NULL vs zero
*How do you stop SQL Server from running?
*32 bit Vs 64 bits
*What is a file
*How do you move a table to a different filegroup
*What is MSDB
*What is MARS
*What is Cluster
*What is Instant Initialization
*Where do you use OPENROWSET
*Profiler Vs Trace
*How do you rebuild index through code
*what is asymmetric Key or how do you use encryption in SS?
*READ_COMMITTED_SNAPSHOT Vs ALLOW_SNAPSHOT_ISOLATION
*How do you send email in SS?
*What is merge join
*OLAP Vs OLTP
*How many MB is a TB?
*SUSER_SNAME vs USER_NAME
*What is a Synonym
*what is a Certificate?
*What is AWE?
*How do you find the size of a table/index/database?
of course.. this be a lot longer list, too.. I'll stop here...
-Dan
October 21, 2009 at 12:05 pm
"How do you move a table to a different filegroup" is not a simple question, some of the senior DBA's that i have interviewed couldn't answer this question 🙂
Amol
Amol Naik
October 21, 2009 at 12:24 pm
*Difference between delete and truncate
One starts with a "d" the other with a "t", and then the rest of the letters
*What is identity column?
It's where they check your age when you go into a bar
*Login vs User
One involves chopping down trees, the other is someone who takes advantage of women
*What are Collations
Things that happen in a database
*CAST Vs CONVERT
The first is throwing, the second is changing your religion
*Union Vs Union All
The North during the war, and then after the war
*What is ANSI
One Spanish "yes"
*View vs Table
Looking at something vs what you eat on
*SPs Vs Functions
I've got a good Scientology joke on this one, but it won't translate well
*What is dynamic SQL?
The opposite of passive SQL
*SQL Vs Windows Authentication
The fight of the century! 10 rounds! Two enter the ring, one leaves!
*How do you find who are the active users in the database
Yell, really loud, "who's using the database?"
*What is database fragmentation
When it explodes and little metal pieces shred everything nearby
*RAID 5 Vs 10
Some boss mobs take more people than a 5-man raid can handle
*What is DMV
Where you get your driver's license
*NULL vs zero
I'm not sure what value Null has, so it's really hard to answer this one
*How do you stop SQL Server from running?
Tell it that it's not safe
*32 bit Vs 64 bits
You have to break everything one more time
*What is a file
What you use for smoothing the edges of your fingernails
*How do you move a table to a different filegroup
Hire a U-Haul truck...
*What is MSDB
Four letters, not in alphabetical order
*What is MARS
A candy bar
*What is Cluster
Didn't he get killed by indians?
*What is Instant Initialization
It's when you get into a college frat just by walking in the door
*Where do you use OPENROWSET
When you have a closed rowset
*Profiler Vs Trace
Not quite the fight of the century, but it should still be on pay-per-view
*How do you rebuild index through code
You just have to use a lot of kleenex
*what is asymmetric Key or how do you use encryption in SS?
A key that's got different sides that you can use to trick Nazi police
*READ_COMMITTED_SNAPSHOT Vs ALLOW_SNAPSHOT_ISOLATION
Not even on pay-per-view, might make local cable
*How do you send email in SS?
You can't. They don't exist any more. WW II took care of that.
*What is merge join
It's when you get onto the freeway with other people
*OLAP Vs OLTP
Battle of the acronyms, really boring stuff, can't even charge admission for this
*How many MB is a TB?
Lots
*SUSER_SNAME vs USER_NAME
The same, but one has a lisp
*What is a Synonym
I think I know this by a different name
*what is a Certificate?
It's what you can get if you're certifiable
*What is AWE?
When something is really, really incredible and totally cool
*How do you find the size of a table/index/database?
Look the last place where you saw it
- Gus "GSquared", RSVP, OODA, MAP, NMVP, FAQ, SAT, SQL, DNA, RNA, UOI, IOU, AM, PM, AD, BC, BCE, USA, UN, CF, ROFL, LOL, ETC
Property of The Thread
"Nobody knows the age of the human race, but everyone agrees it's old enough to know better." - Anon
October 21, 2009 at 12:35 pm
GSquared
I had to stop reading as I was not able to stop laughing out loud
Good creativity
Dan
October 21, 2009 at 12:39 pm
You're hired Gus... when can you start?:-D
October 21, 2009 at 12:58 pm
repent_kog_is_near (10/21/2009)
talltop-969015You asked some simple 'baby' questions.. here they are..
*Difference between delete and truncate
*What is identity column?
*Login vs User
*What are Collations
*CAST Vs CONVERT
*Union Vs Union All
*What is ANSI
*View vs Table
*SPs Vs Functions
*What is dynamic SQL?
*SQL Vs Windows Authentication
*How do you find who are the active users in the database
*What is database fragmentation
*RAID 5 Vs 10
*What is DMV
*NULL vs zero
*How do you stop SQL Server from running?
*32 bit Vs 64 bits
*What is a file
*How do you move a table to a different filegroup
*What is MSDB
*What is MARS
*What is Cluster
*What is Instant Initialization
*Where do you use OPENROWSET
*Profiler Vs Trace
*How do you rebuild index through code
*what is asymmetric Key or how do you use encryption in SS?
*READ_COMMITTED_SNAPSHOT Vs ALLOW_SNAPSHOT_ISOLATION
*How do you send email in SS?
*What is merge join
*OLAP Vs OLTP
*How many MB is a TB?
*SUSER_SNAME vs USER_NAME
*What is a Synonym
*what is a Certificate?
*What is AWE?
*How do you find the size of a table/index/database?
of course.. this be a lot longer list, too.. I'll stop here...
-Dan
Thank you sir! Finally someone addresses my original post.. Amazing! You would be surpised how many people even Senior DBA's do not know the answers to even these "baby" questions..No need for convoluted broken chains and missing log file questions.. Stick to the basics first and you will probably find out what you need to know,,,After all, your goal is not to stump the candidate but accurately guage his basic overall knowledge...
"Technology is a weird thing. It brings you great gifts with one hand, and it stabs you in the back with the other. ...:-D"
October 21, 2009 at 1:12 pm
if Senior DBA's do not know the answers to these questions, what were they doing at work, while gathering their experience?
I would expect the junior DBA with a modest experience to be able to give answer to most, if not all of these simple questions.
If they were thrust into their job, I can understand, but then you cannot call them 'senior', yet.
Time & opportunity and aptitude to grasp & interest/commitment will make that person experienced.
-Dan.
October 21, 2009 at 1:18 pm
"How do you move a table to a different filegroup" is not a simple question, some of the senior DBA's that i have interviewed couldn't answer this question [Smile]
---------------
Amol
Granted, no one is going to have worked on everything under the sun. But if they worked enough around tables and indexes and filegroups, they might have caught it, just out of interest. But given that a DBA can have so many different hats, and in some companies only some hats are worn based on business needs/emphasis, i can understand if this senior DBA did not know this one item, but if he proved his real experience in other ways/areas, then everyone is happy.
Sometime, though, DBA's have to be content wearing the Junior DBA hat till they gather more experiences from real life database challenges/crisis and also learn from their superiors.
Everyone should be learning and also be honest about what they can offer.
Dan
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