Each key appears only once in the index - Oracle Clusters

Q.  When estimating the size of cluster indexes remember that the index is on each cluster key, not the actual rows. Therefore, each key appears only once in the index.
- Published on 12 Aug 15

a. True
b. False

ANSWER: True
 

    Discussion

  • Nirja Shah   -Posted on 01 Oct 15
    - You alter cluster indexes exactly as you do other indexes.

    - When estimating the size of cluster indexes, remember that the index is on each cluster key, not the actual rows. Therefore, each key appears only once in the index.

    - Indexes are optional structures associated with tables and clusters that allow SQL statements to execute more quickly against a table.

    - Just as the index in this manual helps you locate information faster than if there were no index, an Oracle Database index provides a faster access path to table data.

    - You can use indexes without rewriting any queries.

    - Your results are the same, but you see them more quickly.

    - Oracle Database provides several indexing schemes that provide complementary performance functionality.

    - Indexes are logically and physically independent of the data in the associated table. Being independent structures, they require storage space.

    - You can create or drop an index without affecting the base tables, database applications, or other indexes.

    - The database automatically maintains indexes when you insert, update, and delete rows of the associated table.

    - If you drop an index, all applications continue to work. However, access to previously indexed data might be slower.

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