Very Wide table
DBAsupport.com Forums - Powered by vBulletin
Results 1 to 6 of 6

Thread: Very Wide table

Hybrid View

  1. #1
    Join Date
    Mar 2001
    Location
    New York , New York
    Posts
    577
    Hi,

    we have table here with has about 800 columns and 4 million records.

    What is the best way in terms of extent sizes,storage parameters etc for this table.

    The average row size is approximatedly 700 Bytes.

    Thanks

    Ronnie
    ronnie_yours@yahoo.com

    You can if you think you can.

  2. #2
    Join Date
    Apr 2001
    Location
    Louisville KY
    Posts
    295
    I would need additional information before sticking my foot in my mouth.

    How is the table used? Mostly reports using full table scans or transaction lookups going for 1 or two rows?

    How frequently udpated? And how (row by row changes or just insert/appends?)

    Of the 800 columns, are there any clusters of usage (such as there are 15 reports that use the first 20 columns, 30 reports that use the last 30 and 2 that use them all?) This number of columns automatically raises a vertical partitioning flag in my mind.

    Are any of the fields BLOBS/CLOBS/Raw?

    Yada Yada Yada.
    Joseph R.P. Maloney, CSP,CDP,CCP
    'The answer is 42'

  3. #3
    Join Date
    Dec 2001
    Posts
    221
    Originally posted by jrpm
    Answer is 42


    whats that
    Santosh Jadhav
    8i OCP DBA

  4. #4
    Join Date
    Aug 2001
    Location
    Waterloo, On
    Posts
    547
    In my opinion, (and its purely intutional), the table must be split into several small tables. There will always be performance issues related with a table of 800 columns. Unless absolutely necessary, I think I will go with several small tables and join them through a common key. You can even go with clustering if two or more tables are routinely joined.

    Raminder Singh

    Oracle Certified DBA: Oracle 8i, 9i


    Mail me at raminderahluwalia@rediffmail.com.

  5. #5
    Join Date
    Aug 2001
    Location
    Waterloo, On
    Posts
    547
    700 bytes for data in 800 columns. Are you sure??

    Raminder Singh

    Oracle Certified DBA: Oracle 8i, 9i


    Mail me at raminderahluwalia@rediffmail.com.

  6. #6
    Join Date
    Dec 2000
    Location
    Ljubljana, Slovenia
    Posts
    4,439
    Originally posted by Raminder
    700 bytes for data in 800 columns. Are you sure??
    Obviously the majority of trailing columns are empty (contain NULLs).
    Jurij Modic
    ASCII a stupid question, get a stupid ANSI
    24 hours in a day .... 24 beer in a case .... coincidence?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Click Here to Expand Forum to Full Width