Exclusive lock - Multiple updates cannot be made to same resource at same time - Database

Q.  Which type of lock ensures that multiple updates cannot be made to the same resource at the same time?
- Published on 26 Aug 15

a. Schema
b. Shared
c. Exclusive
d. Intent

ANSWER: Exclusive


  • Nirja Shah   -Posted on 02 Nov 15
    - The different types of locks are as follows:
    Shared (S)
    - It is used for read operations that do not change or update data, such as a SELECT statement.

    Update (U)
    - They are used on resources that can be updated. Prevents a common form of deadlock that occurs when multiple sessions are reading, locking, and potentially updating resources later.

    Exclusive (X)
    - They are used for data-modification operations, such as INSERT, UPDATE, or DELETE. Ensures that multiple updates cannot be made to the same resource at the same time.

    - They are used to establish a lock hierarchy. The types of intent locks are: intent shared (IS), intent exclusive (IX), and shared with intent exclusive (SIX).

    - They are used when an operation dependent on the schema of a table is executing. The types of schema locks are: schema modification (Sch-M) and schema stability (Sch-S).

    Bulk Update (BU)
    - They are used when bulk copying data into a table and the TABLOCK hint is specified.

    - It protects the range of rows read by a query when using the serializable transaction isolation level.
    - It ensures that other transactions cannot insert rows that would qualify for the queries of the serializable transaction if the queries were run again.

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