The NOLOGGING mode in SQL statements is a tool used to reduce redo operations, but NOLOGGING does not apply to every operation for which the attribute is set. Which three SQL statements can use the NOLOGGING mode to reduce redo operations? (Choose three)
A. UPDATE
B. CREATE INDEX
C. ALTER INDEX.. REBUILD
D. Conventional Path INSERT
E. CREATE TABLE…. AS SELECT
Answer B C E
Explanation:
You can use the NOLOGGING mode to create index, to rebuild index and to create table as select from the other table.
Incorrect Answers
A: It cannot be used for DML operations itself. Only table can be switched to this mode and than UPDATE command can be performed for the table.
D: Conventional Path INSERT cannot use it. Once the NOLOGGING attribute is set on a table, redo entry generation will be suppressed for all subsequent DML on the table only when that DML is of the following types: Direct Path loads using SQL*Loader, direct load inserts using the /*+ APPEND*/ hint.
OCP: Oracle 9i Performance Tuning Study Guide, Joseph C. Johnson, p. 335-336
Chapter 7: Tuning Redo Mechanisms
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