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pareshmotiwala
Constraint Violating Yak Guru
323 Posts |
 Posted - 2008-01-09 : 13:37:32
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| What SQL Server configuration options can affect the disk pressure caused by the database? How do you find good values for those options?RegardsParesh MotiwalaBoston, USA |
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eyechart
Master Smack Fu Yak Hacker
3575 Posts |
Posted - 2008-01-09 : 14:26:59
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| disk pressure?do you mean heavy disk i/o?reducing disk i/o is the single biggest thing you can do to improve performance. this can be done by tuning queries to be more efficient and thus reducing the amount of buffer cache needed for each query. you can use perfmon to look at SQL buffer cache hit ratio, SQL target and total system memory as well as current disk queueing to see if you are having problems in this area. Look these counters up to see what they mean and how they should be interpreted.using tools like sql profiler you can find queries that run a long time, have heavy reads or heavy writes and tune accordingly. -ec |
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pareshmotiwala
Constraint Violating Yak Guru
323 Posts |
Posted - 2008-01-09 : 14:35:36
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| EyeChart, I think you are right, it is about disk i/o. but what server level config options can affect that? what are the good values and how to find themRegardsParesh MotiwalaBoston, USA |
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pareshmotiwala
Constraint Violating Yak Guru
323 Posts |
Posted - 2008-01-09 : 15:01:43
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| At what point (# of GB of RAM) do you stop using the /3GB switch? Why?RegardsParesh MotiwalaBoston, USA |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2008-01-09 : 15:22:56
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| if u want to use more than 2GB ram, need /3GB unless running 64 bit version.Page Life Expectancy is superior counter to buffer cache hit ratio, though cache hit ratio less than 99% is indicative of memory pressure. PLE < 300 is definite indicator of memory pressure.i/o pressure is measured by reads/writes per second. also avg disk queue length (among others). do u think u have i/o pressure? what symptoms are u seeing? |
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pareshmotiwala
Constraint Violating Yak Guru
323 Posts |
Posted - 2008-01-09 : 15:24:31
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| This is the question that was asked of me in an interview. Sorry, I should have stated this earlier.RegardsParesh MotiwalaBoston, USA |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2008-01-09 : 15:32:13
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so u need "immediate help" so u can go back in there and tell your prospective employer the answer, like u knew it all along...?   |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2008-01-09 : 15:33:29
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| Can I bring Peso and Tara with me on my next job interview? |
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pareshmotiwala
Constraint Violating Yak Guru
323 Posts |
Posted - 2008-01-09 : 15:40:44
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| I am sorry, if I upset some feathers, but ignoring that undertone,lets move forward.They have asked me these questions as an open book.Believe it or not, I have some Oracle questions which were painlessly answered in Oracle forum, and I have put that down as my source of information. So please try to help.RegardsParesh MotiwalaBoston, USA |
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eyechart
Master Smack Fu Yak Hacker
3575 Posts |
Posted - 2008-01-09 : 15:41:50
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| I think I answered your first question appropriately enough for an interview.the 3GB switch is used for 32bit systems only when you have less than 16GB RAM. actually, using /3GB on a system with more than 12GB RAM is problematic as well. do some searching in these forums for discussion about that. If I were asking the interview questions I would also ask you what editions of sql server support the /3GB switch.Stick around here watch and participate and you will be surprised how quickly you learn.-ec |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2008-01-09 : 15:44:59
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didnt ruffle any feathers. just having fun with you is all. "immediate help" usually sounds like "im having trouble right now with my servers" to me |
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eyechart
Master Smack Fu Yak Hacker
3575 Posts |
Posted - 2008-01-09 : 15:48:44
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quote:
Originally posted by pareshmotiwala
I am sorry, if I upset some feathers, but ignoring that undertone,lets move forward.They have asked me these questions as an open book.Believe it or not, I have some Oracle questions which were painlessly answered in Oracle forum, and I have put that down as my source of information. So please try to help.
wow, just saw this. Normally I would not be helping someone cheat on an interview or a test, but I will leave my other response.so, you have interview questions and they let you ask other people for the answers? what kind of interview is that?-ec |
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pareshmotiwala
Constraint Violating Yak Guru
323 Posts |
Posted - 2008-01-09 : 16:27:35
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| no offense taken, thanks for so many offers to help.RegardsParesh MotiwalaBoston, USA |
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immediate help please?