Results 1 to 4 of 4
  1. #1
    Join Date
    Feb 2009

    Unanswered: update in table pertitioned by hash

    Hi there,

    I have a table partitioned by hash. I want to make some updates (not on the partition key column). Do I need to specify partition name in the query or the DB server will "direct" the update to the proper partition based on the key?

    Thanks in advance

  2. #2
    Join Date
    Aug 2003
    Where the Surf Meets the Turf @Del Mar, CA
    Provided Answers: 1
    I expect it would be faster to simply try the SQL yourself rather than wait for an answer; which could even be wrong.
    You can lead some folks to knowledge, but you can not make them think.
    The average person thinks he's above average!
    For most folks, they don't know, what they don't know.
    Good judgement comes from experience. Experience comes from bad judgement.

  3. #3
    Join Date
    Feb 2009
    true thing is that I'm having just limited Oracle knowledge and I do not know a way to check how the update works, i.e. is the update went directly to the partition;

    my guess is that if the update is based on the partition key than one don't need to specify the partition name in the statement (as hash value can be calculated from the "where" parameter), otherwise is needed, cause it will need first to identify the rows that fit the condition in the update and then to find out in which partition they reside;

    anyways, believe me that I have tried to find the answer myself before posting...

    I guess I can say the same for you: it will not be better not to answer if you don't have anything to say?!

  4. #4
    Join Date
    Sep 2002
    Oracle will update the rows that need updated, period. The question is how well will the update perform. Without having more detail, it's difficult to predict. As was previously mentioned, test the update and see if it preforms as well as expected.

    As for "checking how the update works", you should run a query that looks at the data before the update, run the update, and then run the query to look at the data again to see if the update worked properly. After you have determined if it worked properly, you can either commit or rollback, as the case may be.

    As for helping to predict performance, you should read and learn about Explain plans.

Posting Permissions

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