Results 1 to 4 of 4
  1. #1
    Join Date
    Feb 2004
    Location
    Chennai
    Posts
    53

    Unanswered: local & global indexes

    can anyone give an idea abt local and global indexes
    -Mathan
    For a quick pocket reference of oracle refer http://pocketoracle.blogspot.com/

  2. #2
    Join Date
    Sep 2002
    Location
    UK
    Posts
    5,171
    Provided Answers: 1
    For a partitioned table:
    Local = an index per partition
    Global = one index for whole table (all partitions)

  3. #3
    Join Date
    Oct 2003
    Posts
    706
    The essential idea is that all of the I/O needed to look-up and then retrieve the data, from a particular segment of this (presumably enormously-huge...) table, could be handled entirely by a particular drive or set of drives.

    Otherwise, the I/O load of accessing the index would be concentrated on those drives that carry the (global) index, creating a natural bottleneck at that location and causing the data-drives to be under-utilized (because "you can't get it until you know where to find it").

    It's important to remember that there is no "always do it this way or that way" rule to be applied here. It depends on your workload, your situation, and the bottlenecks you have observed with your measurements. It also depends on your tolerance for downtime in the event of "Mister Murphy."
    ChimneySweep(R): fast, automatic
    table repair at a click of the
    mouse! http://www.sundialservices.com

  4. #4
    Join Date
    Apr 2003
    Location
    Minneapolis, MN
    Posts
    273
    Quote Originally Posted by getmathan
    can anyone give an idea abt local and global indexes
    There is a lot more on this topic, but I would like to seggest a book where you find very good arguments on this.

    Practical Oracle 8i By Jonathan Lewis.
    Bhavin

    MS Computer Science
    OCP DBA 9i/8i

Posting Permissions

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