Results 1 to 8 of 8
  1. #1
    Join Date
    Dec 2003
    Location
    India
    Posts
    7

    Question Unanswered: Query Merging/ Query Transformation ???

    Hello,

    Can someone plz refer/recommend any document on query merging? I am working on a database sever. The response time, of view's query has become a challange to me. I have tried everything, the last hope left is query merging.
    But I didnt find any docs/papers/books on it.

    Plz help.
    Shigs.
    =============================
    Are there those,
    In this world of brave,
    Who can tell me,
    How should I behave,
    When I am disgraced.
    =============================

  2. #2
    Join Date
    Aug 2002
    Location
    Scotland
    Posts
    1,578
    Could you please explain on the term Query merging.

    If you want to merge certain table in the query you can use JOINs, refer to books online for more information.
    --Satya SKJ
    Microsoft SQL Server MVP
    [IMG]http://sqlserver-qa.net/google_bart.gif[/IMG]

  3. #3
    Join Date
    Aug 2002
    Location
    Scotland
    Posts
    1,578
    Could you please explain on the term Query merging.

    If you want to merge certain table in the query you can use JOINs, refer to books online for more information.
    --Satya SKJ
    Microsoft SQL Server MVP
    [IMG]http://sqlserver-qa.net/google_bart.gif[/IMG]

  4. #4
    Join Date
    Dec 2003
    Location
    India
    Posts
    7

    Red face The term *Query Merging*

    Hi Satya

    Thanks a lot. Query Merging that I referred was not related to merging of one table's data into another, but if I fire a query, which is containing a subquery in it, then the execution may take two different strategies, 1. Execute the subquery, fetch the result and compare this data with the parent querie's data. 2. Merge the subquery into Parent query and execute them as if the query wasn't subquery but a single level '0' query.

    The best xample is Oracle's COMPLEX_QUERY_MERGING option. I want to understand, how Oarcle internally merges these queries? Is there any Optimizer Doc, which gives the detail?

    Waiting...

  5. #5
    Join Date
    Jun 2003
    Location
    Ohio
    Posts
    12,592
    Provided Answers: 1
    Is your question in regards to Oracle? This is a SQL Server forum, and SQL Server generally does a good job of optimizing queries, even with complex embedded subqueries.
    If you are having slow response times on SQL Server, then post your query and someone on the forum might be able to help you optimize it.
    If it's not practically useful, then it's practically useless.

    blindman
    www.chess.com: "sqlblindman"
    www.LobsterShot.blogspot.com

  6. #6
    Join Date
    Aug 2002
    Location
    Scotland
    Posts
    1,578
    You can check the execution plan of that query in query analyzer which gives you better idea about the table scans and performance.
    --Satya SKJ
    Microsoft SQL Server MVP
    [IMG]http://sqlserver-qa.net/google_bart.gif[/IMG]

  7. #7
    Join Date
    Nov 2002
    Location
    Jersey
    Posts
    10,322
    I have a question...are there fewer and fewer Oracle projects out there these days?
    Brett
    8-)

    It's a Great Day for America everybody!

    dbforums Yak CorralRadio 'Rita
    dbForums Member List
    I'm Good Once as I ever was

    The physical order of data in a database has no meaning.

  8. #8
    Join Date
    Jun 2003
    Location
    Ohio
    Posts
    12,592
    Provided Answers: 1
    One can only hope...
    If it's not practically useful, then it's practically useless.

    blindman
    www.chess.com: "sqlblindman"
    www.LobsterShot.blogspot.com

Posting Permissions

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