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Thread: indexes love big blocks

  1. #51
    Join Date
    Nov 2002
    Location
    Geneva Switzerland
    Posts
    3,142
    Originally posted by gandolf989
    DaPi, fess up! I bet you own a Citron! Either that or an AMC Gremlin!!!
    Either way, you definitely seem like the bow tie type!!!
    OK, if its "kiss and tell time":

    I've never used a pocket protector. I often wear a bow tie, but only with DJ (smoking/tuxedo or whatever it's called in your part of the world) or tails. Moderate over-bite. 5'10" 70Kg. Hair thining but no bald patch yet - getting a bit grey around the temples. Previous car was an Irmscher Opel i200 (blissful engine/gear-box combination) . . . the one in process of reconstruction is a 1929 Riley "9", in the family since 1933.

    The only Citroën I've driven was a 1923 model (I think). Very slow, very exciting because the accelerator and brake pedals were the other way round!

    P.S. No I don't own a lemon

    P.P.S. I'll take this opportunity to plug a motor meeting arranged by a buddie each year: http://www.british-cars.ch/images2.html
    Etrance free, 1'500 cars . . .
    Last edited by DaPi; 04-16-2005 at 02:16 PM.
    "The power of instruction is seldom of much efficacy except in those happy dispositions where it is almost superfluous" - Gibbon, quoted by R.P.Feynman

  2. #52
    Join Date
    Nov 2000
    Location
    Pittsburgh, PA
    Posts
    4,166
    Originally posted by DaPi
    OK, if its "kiss and tell time":

    I've never used a pocket protector. I often wear a bow tie, but only with DJ (smoking/tuxedo or whatever it's called in your part of the world) or tails. Moderate over-bite. 5'10" 70Kg. Hair thining but no bald patch yet - getting a bit grey around the temples. Previous car was an Irmscher Opel i200 (blissful engine/gear-box combination) . . . the one in process of reconstruction is a 1929 Riley "9", in the family since 1933.

    The only Citroën I've driven was a 1923 model (I think). Very slow, very exciting because the accelerator and brake pedals were the other way round!

    P.S. No I don't own a lemon

    P.P.S. I'll take this opportunity to plug a motor meeting arranged by a buddie each year: http://www.british-cars.ch/images2.html
    Etrance free, 1'500 cars . . .
    Now this is a nice family car!



    I don't know what a 1929 Riley "9" is, but can you post a picture?

  3. #53
    Join Date
    Apr 2005
    Posts
    17

    larger block sizes

    Nope, haven't had time to do the 32k trial, especially since I don't have a 64 bit server to play with (yet). As soon as I can I will look into it.

    Mike
    Michael R. Ault
    Senior Consultant
    Burleson Consulting

  4. #54
    Join Date
    Nov 2002
    Location
    Geneva Switzerland
    Posts
    3,142
    Originally posted by gandolf989
    Don't know what a 1929 Riley "9" is, but can you post a picture?
    None of these mine (it's in bits at the moment):

    http://web.ukonline.co.uk/rileyrob/i...rer_pn3026.jpg

    http://web.ukonline.co.uk/rileyrob/i...rer_vp8554.jpg

    P.S. there was a racing "9" - some people still race them: http://web.ukonline.co.uk/rileyrob/i...pec_ww9736.jpg
    OUCH!
    Last edited by DaPi; 04-16-2005 at 03:47 PM.
    "The power of instruction is seldom of much efficacy except in those happy dispositions where it is almost superfluous" - Gibbon, quoted by R.P.Feynman

  5. #55
    Join Date
    Nov 2000
    Location
    Pittsburgh, PA
    Posts
    4,166

    Re: larger block sizes

    Originally posted by mikerault
    Nope, haven't had time to do the 32k trial, especially since I don't have a 64 bit server to play with (yet). As soon as I can I will look into it.

    Mike
    Do you think that there could be a problem with an article that over generalizes a rule of thumb?

  6. #56
    Join Date
    Apr 2005
    Posts
    29

    Re: larger block sizes

    Originally posted by mikerault
    Nope, haven't had time to do the 32k trial, especially since I don't have a 64 bit server to play with (yet). As soon as I can I will look into it.

    Mike

    One other thing about Mikes "Rules" for large blocksizes paper. He says

    This is very true. All temp segment access is sequential and 32k blocksizes greatly reduce logical I/O and disk sort times. I'm working an a benchmark right now that shows a one-third speed improvement of disk sorts in a 32k vs. an 8k blocksize.

    Mike, thought you were working on that benchmark for a while. but anyway, can you explain what that paragraph means?

    Why is it better to read

    4x32k blocks for 128k versus
    16x8k blocks for 128k

    since temp is read just using multi-block IO's like a full scan? It reads N kb of information, it does not read a block (so, it boils down to 6 one way and 1/2 dozen the other, we read 128k -- or Nk in general)


    And also, since TEMP does not do LIO at all, what is the comment about LIO? what does that mean exactly.

    See this posting for the entire discussion.
    Last edited by TomKyte; 04-16-2005 at 04:08 PM.

  7. #57
    Join Date
    Nov 2004
    Location
    Mumbai, India
    Posts
    452
    Originally posted by TomKyte
    Now, I'm just hoping my wife doesn't google me to see what I've been up to now.... [/B]
    May be she has and waiting for the right moment
    There are three kinds of lies: Lies, damned lies, and benchmarks...

    Unix is user friendly. It's just very particular about who it's friends are.

    Oracle DBA

  8. #58
    Join Date
    Jul 2002
    Location
    Northampton, England
    Posts
    612
    Originally Posted by DaPi
    P.P.S. I'll take this opportunity to plug a motor meeting arranged by a buddie each year: http://www.british-cars.ch/images2.html


    Thats the car I have hired for my wedding later in the year!!
    Assistance is Futile...

  9. #59
    Join Date
    Aug 2002
    Location
    Colorado Springs
    Posts
    5,253

    Re: Re: larger block sizes

    Originally posted by TomKyte
    since temp is read just using multi-block IO's like a full scan? It reads N kb of information, it does not read a block (so, it boils down to 6 one way and 1/2 dozen the other, we read 128k -- or Nk in general)


    And also, since TEMP does not do LIO at all, what is the comment about LIO? what does that mean exactly.

    See this posting for the entire discussion.
    Don't hold your breath ... I asked Mike about this on Mar 8th http://dba.ipbhost.com/index.php?showtopic=1239&st=30
    David Aldridge,
    "The Oracle Sponge"

    Senior Manager, Business Intelligence Development
    XM Satellite Radio
    Washington, DC

    Oracle ACE

  10. #60
    Join Date
    Apr 2005
    Posts
    29

    Re: Re: Re: larger block sizes

    Originally posted by slimdave
    Don't hold your breath ... I asked Mike about this on Mar 8th http://dba.ipbhost.com/index.php?showtopic=1239&st=30
    Watch out or he'll take you to task

    Based on that I'm sure he'll be back to answer.

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