SQL Server Performance

A strange phenomena

Discussion in 'SQL Server 2005 Performance Tuning for DBAs' started by megalith, Mar 17, 2007.

  1. megalith New Member

    I create a new DB just as same as the previous one. I use this new DB for my business (new data inserting to this new DB), after running for a while (about 1 hour), I import my history data from the old DB into the new one.
    When all this been finished, I find a phenomena very schange. When I query data for last 1 days, it's rather slow; while query data for rencent 30 days, it is quick as before. When querying data 2 days before for any period (1 day or n days), it is quick as before.
    I don't know why. Can any one give me an answer. Thanks.

    I use cluster index at date column and a replication at the tables queried on.
  2. joechang New Member

  3. MohammedU New Member

  4. mmarovic Active Member

    Is your query inserting historical data ordered by dat column? Have you rebuilt clustered index after insert? Does index on date use ascending order?
  5. satya Moderator

    Even though auto update statistics is enabled, it is better to run intermittent update stats to ensure the performance is gained as explained by Joe above.

    Satya SKJ
    Microsoft SQL Server MVP
    Writer, Contributing Editor & Moderator
    This posting is provided AS IS with no rights for the sake of knowledge sharing. The greatest discovery of my generation is that a human being can alter his life by altering his attitudes of mind.

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