September 21, 2012 at 11:51 am
Lowell (9/21/2012)
ok, I have my own my knee jerk reactions for the things to review.Grant wanted to avoid putting the answers on the forum, but i'd kind of like to see how i would stack up agaisnt other's ideas.
should i post my ideas out here or keep them to myself?
Keep 'em to yourself. And I'm with Gail. Memory is not the first place I'd go either. But see, it's a fun, or extremely painful, question. And there's no way you can really study for it.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning
September 21, 2012 at 11:55 am
CptCrusty1 (9/21/2012)
=====UPDATE=====We brought a guy in that indicated he was very experienced as a dba. He had lots of stuff on the resume that sounded right.
As it turns out, he freely admitted to using nefarious methods to get done what needed done rather than go through official channels to ask for access, etc. Not a good thing to say during an interview; however, it really put a cloud over the interview.
He seemed to trip all over some of the questions and we just didn't get a good feel.
Thankfully, I've been reading ya'lls stuff and decided pretty quickly he wasn't a match....
Thanks all for the help and input on this.. I'm getting quite an education into the dark underbelly of the DBA world. It's apparently not all peaches and cream....
Will post more as progress is made.
Thanks
Crusty.
Yeah, it can get pretty darn dark! Definitely.
- 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
September 21, 2012 at 1:38 pm
Please fee free to PM me on these ideas if you wish to keep them off public consumption.... I gotta use em for the interviews....
September 21, 2012 at 1:59 pm
CptCrusty1 (9/21/2012)
Please fee free to PM me on these ideas if you wish to keep them off public consumption.... I gotta use em for the interviews....
Crusty, where are you located at? If it's local to one of the regulars you trust they could probably swing giving you a hand in the interviews for a reasonable fee.
I personally start off with 'simple questions' to break the 'oh god I'm in an interview!' fear that just about every interviewee comes in with. It's just natural tension. Then I'll start drilling. I usually avoid open ended questions like Grant does because I've found they can wander around far too much sometimes. I'll leave that as a final. I've closed out interviews inside of 3 minutes before however when it's painfully obvious that I'm being smoke and sunshined, however.
Never stop learning, even if it hurts. Ego bruises are practically mandatory as you learn unless you've never risked enough to make a mistake.
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October 1, 2012 at 1:26 pm
Crusty, where are you located at? If it's local to one of the regulars you trust they could probably swing giving you a hand in the interviews for a reasonable fee.
I know the smoke and Sunshine bit too... unfortunately. When I was an Access dude, I interviewed a guy that billed himself off as an Access Expert. He though he was an expert until I asked him some mediocre questions... short interview... His last words before he left were "I didn't know you could do that." :w00t:
OK... I'm located in (BARF) Houston, TX.
October 1, 2012 at 1:33 pm
OK... so here's a question for you serious DBA's.
My DBA Vendor indicated that they had to delete indexes before creating primary key's on a table. They created the primary key, and then had trouble recreating one of the indexes. They were creating a Unique Index and it failed due to duplicate values found. This raises several questions.
Why are they deleting Indexes before creating a PK. Shouldn't this be a very simple thing to add a constraint? I've never heard of doing this in this particular way.
If the index failed due to duplicate values and it doesn't involve the PK field. My understanding is that using a Unique Index is similar to creating a PK in that it's enforcing a unique combination of values for the fields used. In this case, when I looked for duplicate values, I found thousands. This tells me they were either using the wrong type of index, or something drastic happened to the data.
Any feedback would be helpful....
There is a list of things I don't like about this vendor, but that's a different story.
October 1, 2012 at 1:58 pm
CptCrusty1 (10/1/2012)
OK... so here's a question for you serious DBA's.My DBA Vendor indicated that they had to delete indexes before creating primary key's on a table. They created the primary key, and then had trouble recreating one of the indexes. They were creating a Unique Index and it failed due to duplicate values found. This raises several questions.
Why are they deleting Indexes before creating a PK. Shouldn't this be a very simple thing to add a constraint? I've never heard of doing this in this particular way.
If the index failed due to duplicate values and it doesn't involve the PK field. My understanding is that using a Unique Index is similar to creating a PK in that it's enforcing a unique combination of values for the fields used. In this case, when I looked for duplicate values, I found thousands. This tells me they were either using the wrong type of index, or something drastic happened to the data.
Any feedback would be helpful....
There is a list of things I don't like about this vendor, but that's a different story.
I'd move this question to a different thread, since it's not about interview questions.
I've never had to drop indexes to create a PK on a table. You'd have to do so if there was already a PK on the table, but only the one supporting the PK constraint.
I'm not sure how you'd get duplicates into columns with a Unique Index on them. Unless the index was filtered and they were outside the filter, but that should show in the create script for the index. Would have a "Where" clause on it. So, either the original index was not unique, and they're trying to create a unique index now, or it had different columns, or something like that.
When they dropped the indexes, did they back up the database first? Did they script out the create statements for the indexes before dropping them? Or did they just write down a list of indexes and try to re-create them through the GUI or something like that?
- 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 1, 2012 at 2:08 pm
GS, the questions KIND OF relate in that the whole reason I'm trying to interview a DBA is because this vendor stinks. The questions are a direct indicator of that.
So far, no one is fessing up. The columns for the index are in no way unique... Not sure why they're doing things this way.
I got a resume for what looks to be a solid candidate.... SO... this thread will come in handy....
October 2, 2012 at 6:53 am
Abu Dina (9/21/2012)
You get a phone call from one the users. They tell you the database is slow. What do you do?
You answer that reasonably well, you're hired. You start talking junk, you're not.
I'd start with the usual suspects like server memory, cpu, disk, network etc.... who said the real problem is with SQl Server anyway?!
am I talking junk yet or am I hired?! 😛
The first two things I'd want to know is
1) How did the user get my phone number? (instead of going through the correct support channels)
2) Slow compared to what?
October 2, 2012 at 8:04 am
CptCrusty1 (10/1/2012)
GS, the questions KIND OF relate in that the whole reason I'm trying to interview a DBA is because this vendor stinks. The questions are a direct indicator of that.So far, no one is fessing up. The columns for the index are in no way unique... Not sure why they're doing things this way.
I got a resume for what looks to be a solid candidate.... SO... this thread will come in handy....
Totally understood.
They definitely sound fishy so far. Having someone in-house who can at least sanity-check them would definitely be advantageous.
("Sanity-check" ... if "body-check" means what it does in hockey, then "sanity-check" = ? :w00t: )
- 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 2, 2012 at 8:07 am
("Sanity-check" ... if "body-check" means what it does in hockey, then "sanity-check" = ? :w00t: )
BUAH!!! LOL, ROFLMAO... that's great... I'd hate to be "Sanity-Checked" at your office... Look up the Youtube video "Terry Tate Office Quarterback" :w00t:
October 2, 2012 at 8:59 am
Grant Fritchey (9/21/2012)
Lowell (9/21/2012)
ok, I have my own my knee jerk reactions for the things to review.Grant wanted to avoid putting the answers on the forum, but i'd kind of like to see how i would stack up agaisnt other's ideas.
should i post my ideas out here or keep them to myself?
Keep 'em to yourself. And I'm with Gail. Memory is not the first place I'd go either. But see, it's a fun, or extremely painful, question. And there's no way you can really study for it.
Why can't you just google "why is sql server running so slow" or something along those lines. I'm already finding reading material, so why can't folks just study that sort of stuff?
October 2, 2012 at 10:25 am
patrickmcginnis59 (10/2/2012)
Grant Fritchey (9/21/2012)
Lowell (9/21/2012)
ok, I have my own my knee jerk reactions for the things to review.Grant wanted to avoid putting the answers on the forum, but i'd kind of like to see how i would stack up agaisnt other's ideas.
should i post my ideas out here or keep them to myself?
Keep 'em to yourself. And I'm with Gail. Memory is not the first place I'd go either. But see, it's a fun, or extremely painful, question. And there's no way you can really study for it.
Why can't you just google "why is sql server running so slow" or something along those lines. I'm already finding reading material, so why can't folks just study that sort of stuff?
Because you can't memorize the answer. You could read three or four of those articles and maybe two of out of three say that you always need to defrag the index to speed up the server. I'll then say "OK, the index is defragmented. Things are still slow, what else could it be?"
And we keep going.
It's not a punishment or a trick. It's just the best way I know to explore someone's depth and breadth of knowledge.
"The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
- Theodore Roosevelt
Author of:
SQL Server Execution Plans
SQL Server Query Performance Tuning
October 2, 2012 at 10:40 am
Grant Fritchey (8/27/2012)
You might want to hire a consultant to do the interview for you. I know several people that are regularly doing interviews for employers that don't have the internal resources to get that interview done properly.
I am late to this party, but that is probably the best reply I have seen on the thread.
Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service
October 2, 2012 at 11:28 am
Grant Fritchey (10/2/2012)
patrickmcginnis59 (10/2/2012)
Grant Fritchey (9/21/2012)
Lowell (9/21/2012)
ok, I have my own my knee jerk reactions for the things to review.Grant wanted to avoid putting the answers on the forum, but i'd kind of like to see how i would stack up agaisnt other's ideas.
should i post my ideas out here or keep them to myself?
Keep 'em to yourself. And I'm with Gail. Memory is not the first place I'd go either. But see, it's a fun, or extremely painful, question. And there's no way you can really study for it.
Why can't you just google "why is sql server running so slow" or something along those lines. I'm already finding reading material, so why can't folks just study that sort of stuff?
Because you can't memorize the answer. You could read three or four of those articles and maybe two of out of three say that you always need to defrag the index to speed up the server. I'll then say "OK, the index is defragmented. Things are still slow, what else could it be?"
So whats the downside of lowell posting his ideas then? Thats what I'm inquiring, whats the difference between lowells ideas getting posted (and read) versus the rest of the info out there?
I'm inquiring why you guys don't post that stuff when its pretty much available anyways. Just curious on this point as I know you guys have made it a point. Is it to protect weak interviewers that you know of?
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