单选题An index called ORD_CUSTNAME_IX has been created on the CUSTNAME column in the ORDERS table using the following command：   SQL>CREATE INDEX ord_custname_ix ON orders（custname）；   The ORDERS table is frequently queried using the CUSTNAME column in the W

第1题：

A warehouse fact table in your Oracle 12c Database is range-partitioned by month and accessed frequently with queries that span multiple partitions The table has a local prefixed, range partitioned index. Some of these queries access very few rows in some partitions and all the rows in other partitions, but these queries still perform a full scan for all accessed partitions. This commonly occurs when the range of dates begins at the end of a month or ends close to the start of a month. You want an execution plan to be generated that uses indexed access when only a few rows are accessed from a segment, while still allowing full scans for segments where many rows are returned. Which three methods could transparently help to achieve this result?（）

• A、Using a partial local Index on the warehouse fact table month column with indexing disabled to the table partitions that return most of their rows to the queries.
• B、Using a partial local Index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.
• C、Using a partitioned view that does a UNION ALL query on the partitions of the warehouse fact table, which retains the existing local partitioned column.
• D、Converting the partitioned table to a partitioned view that does a UNION ALL query on the monthly tables, which retains the existing local partitioned column
• E、Using a partial global index on the warehouse fact table month column with indexing disabling for the table partitions that return most of their rows to the queries.
• F、Using a partial global index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.

第2题：

An index called ORD_CUSTNAME_IX has been created on the CUSTNAME column in the ORDERS table using the following command：   SQL>CREATE INDEX ord_custname_ix ON orders（custname）；   The ORDERS table is frequently queried using the CUSTNAME column in the WHERE clause. You want to check the impact on the performance of the queries if the index is not available. You do not want the index to be dropped or rebuilt to perform this test.  Which is the most efficient method of performing this task？（）

• A、 disabling the index
• B、 making the index invisible
• C、 making the index unusable
• D、 using the MONITORING USAGE clause for the index

第3题：

第4题：

Users in your production database complain that they are getting the following error message while trying to insert rows into the ORDERS table：  ERROR at line 1：  ORA-01654： unable to extend index USERS.ORDERS_IND by 8 in tablespace INDEXES.While investigating， you find that the INDEXES tablespace has run out of space and there is no more free space on the disk where the data files are available. Which two actions could you perform to overcome this error without affecting the queries that are currently being executed？（）

• A、 Drop and re-create the inbox.
• B、 Coalesce the ORDERS_IND index.
• C、 Coalesce the INDEXES tablespace.
• D、 Drop and re-create the ORDERS table.
• E、 Rebuild the index online and move it to another tablespace.

第5题：

Which two operations can be performed on an external table（）

• A、Create a view on the table.
• B、Create an index on the table.
• C、Create a synonym on the table.
• D、Add a virtual column to the table.
• E、Update the table using the UPDATE statement.
• F、Delete rows in the table using the DELETE command.

第6题：

In your test database， you have created the ORDERS table as an index/x7forganized table （IOT）. To facilitate faster querying， you have created a mapping table and a bitmap index on the ORDER_FILLED column. You observe that the query performance degrades when users perform a large volume of transactions.  While investigating the reason， you find that the mapping table segment is fragmented， leading to poor performance. Which option would you use to defragment the mapping table without affecting the original table data？（）

• A、export and import the mapping table
• B、drop and re­create the mapping table
• C、truncate the mapping table and reinsert the values
• D、use the ALTER TABLE .. REBUILD command to defragment the mapping table

第7题：

The ST_INFO master table has millions of rows that are updated very rarely. It has a STATE_CODE column that contains the value for 25 states. The table is frequently queried on the STATE_CODE column. Which type of index would you suggest to improve the query performance？（）

• A、B-tree
• B、bitmap
• C、reverse key
• D、function based

第8题：

订单表Orders的列OrderID的类型是小整型（smallint），根据业务的发展需要改为整型（integer），应该使用下面的哪条语句？（）

• A、ALTER COLUMN OrderID integer FROM Orders
• B、ALTER TABLE Orders（OrderID integer）
• C、ALTER TABLE Orders ALTER COLUMN OrderID integer
• D、ALTER COLUMN Orders.OrderID integer

第9题：

Examine the command that is used to create a table：  SQL> CREATE TABLE orders（oid NUMBER（6） PRIMARY KEY， odate DATE， ccode NUMBER（6）， oamt NUMBER（10，2）） TABLESPACE users；  Which two statements are true about the effect of the above command） （）

• A、A CHECK constraint is created on the OID column.
• B、A NOT NULL constraint is created on the OID column.
• C、The ORDERS table is the only object created in the USERS tablespace.
• D、The ORDERS table and a unique index are created in the USERS tablespace.
• E、The ORDERS table is created in the USERS tablespace and a unique index is created on the OIDcolumn in the SYSTEM tablespace.

第10题：

On your Oracle Database, you issue the following commands to create indexes: SQL > CREATE INDEX oe.ord_customer_ix1 ON oe.orders (customer_id, sales_rep_id) INVISIBLE; SQL> CREATE BITMAP INDEX oe.ord_customer_ix2 ON oe.orders (customer_id, sales_rep_id); Which two statements are true?（）

• A、Only the ORD_CUSTOMER_IX1 index created.
• B、Both the indexes are updated when a row is inserted, updated, or deleted in the ORDERS table.
• C、Both the indexes are created: however, only ORD_CUSTOMERS_IX1 is used by the optimizer for queries on the ORDERS table.
• D、The ORD_CUSTOMER_IX1 index is not used by the optimizer even when the OPTIMIZER_USE_INVISIBLE_INDEXES parameters is set to true.
• E、Both the indexes are created and used by the optimizer for queries on the ORDERS table.
• F、Both the indexes are created: however, only ORD_CUSTOMERS_IX2 is used by the optimizer for queries on the ORDERS table.