default lock for oracle9i
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Thread: default lock for oracle9i

  1. #1
    Join Date
    Apr 2003
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    Malaysia
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    Smile default lock for oracle9i

    hello, i am new user...
    i am using oracle9i database, my boss want me to check the default lock for Oracle9i, either by row or by table or by page.
    and how to check it.


    Thanks.

  2. #2
    Join Date
    Aug 2002
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    Colorado Springs
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    5,253
    Oracle locks at the row level. locks are never escalated to table level -- the locking overhead is extremely low.

    More details can be found in the Oracle Concepts Guide.
    David Aldridge,
    "The Oracle Sponge"

    Senior Manager, Business Intelligence Development
    XM Satellite Radio
    Washington, DC

    Oracle ACE

  3. #3
    Join Date
    May 2002
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    2,645
    Table Locks (TM)
    A transaction acquires a table lock when a table is modified in the following DML statements: INSERT, UPDATE, DELETE, SELECT with the FOR UPDATE clause, and LOCK TABLE. These DML operations require table locks for two purposes: to reserve DML access to the table on behalf of a transaction and to prevent DDL operations that would conflict with the transaction. Any table lock prevents the acquisition of an exclusive DDL lock on the same table and thereby prevents DDL operations that require such locks. For example, a table cannot be altered or dropped if an uncommitted transaction holds a table lock for it.

  4. #4
    Join Date
    Jun 2001
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    Helsinki. Finland
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    Re: default lock for oracle9i

    Originally posted by nor
    hello, i am new user...
    i am using oracle9i database, my boss want me to check the default lock for Oracle9i, either by row or by table or by page.
    and how to check it.


    Thanks.
    Ask that manager, what table locks he is talking about: shared, exclusive...?
    Oracle Certified Master
    Oracle Certified Professional 6i,8i,9i,10g,11g
    email: ocp_9i@yahoo.com

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