#1
  1. No Profile Picture
    Registered User
    Devshed Newbie (0 - 499 posts)

    Join Date
    Aug 2013
    Posts
    1
    Rep Power
    0

    Database Questions


    Hi Guys,

    I have a couple of questions. I will greatly appreciate any help I can get. Thanks in advance

    1. You are given a table (A, B, C) where A is a low-cardinality attribute, B is a high-cardinality attribute, C is a numerical variable. You're asked to produce cross-tabulation of sum of C by both A and B and show resultant table in Excel spreadsheet. Would you choose to show A as columnar dimension? Why?

    2.What key mathematical property of a field is used in deciding if it should belong to an index?

    3.What is the general class of dependencies which uniquely identify every record in a table?
  2. #2
  3. SQL Consultant
    Devshed Supreme Being (6500+ posts)

    Join Date
    Feb 2003
    Location
    Toronto Canada
    Posts
    27,118
    Rep Power
    4274
    1. yes, i would... but i'm weird

    2. that it not be irrational

    3. primary key
    rudy.ca | @rudydotca
    Buy my SitePoint book: Simply SQL
  4. #3
  5. No Profile Picture
    Contributing User
    Devshed Newbie (0 - 499 posts)

    Join Date
    May 2013
    Location
    Usually Japan when not on contract
    Posts
    240
    Rep Power
    12
    So much for discouraging the farming out of verbatim homework questions to the forum...
  6. #4
  7. SQL Consultant
    Devshed Supreme Being (6500+ posts)

    Join Date
    Feb 2003
    Location
    Toronto Canada
    Posts
    27,118
    Rep Power
    4274
    Originally Posted by zxq9
    So much for discouraging the farming out of verbatim homework questions to the forum...
    i wonder if you actually read my answers, chico
    rudy.ca | @rudydotca
    Buy my SitePoint book: Simply SQL

IMN logo majestic logo threadwatch logo seochat tools logo