单项选择题
The table contains a million rows for zonewise analysis in the DSS system. DML operations areperformed very rarely on the table. You decide to prepare an index on the ZONE column to enhance theperformance of the queries on the ZONE column.
Which type of index would you select in this scenario（）
A.Bitmap index
B.Reverse key index
C.Normal B-Tree index
D.Function-based index
相关考题
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单项选择题
You have two tables with referential integrity enforced between them. You need to insert data to thechild table first because it is going to be a long transaction and data for the parent table will be available ina later stage， which can be inserted as part of the same transaction. View the Exhibit to examine the commands used to create tables. Which action would you take to delay the referential integrity checking until the end of the transaction（）
A.Set the constraint to deferred before starting the transaction.
B.Alter the constraint to NOVALIDATE state before starting the transaction.
C.Enable the resumable mode for the session before starting the transaction.
D.Set the COMMIT_WAIT parameter to FORCE_WAIT for the session before starting the transaction. -
多项选择题
You execute this command to drop the ITEM table， which has the primary key referred in the ORDERtable： SQL> DROP TABLE scott.item CASCADE CONSTRAINTS PURGE； Which two statements are true about the effect of the command（）
A.No flashback is possible to bring back the ITEM table.
B.The ORDER table is dropped along with the ITEM table.
C.The dependent referential integrity constraints in the ORDER table are disabled.
D.The dependent referential integrity constraints in the ORDER table are removed.
E.The table definition of the ITEM table and associated indexes are placed in the recycle bin. -
多项选择题
WhichthreedescriptionsarecorrectabouttheeffectsoftheTRUNCATEcommandonatable（）
A.The corresponding indexes for the table are also truncated.
B.Delete triggers on the table are fired during the execution of the TRUNCATE command.
C.The child table is truncated when the TRUNCATE command is applied on the parent table.
D.The high-water mark （HWM） is set to point to the first usable data block in the table segment.
E.No undo or very little undo data is generated during the execution of the TRUNCATE command
