单选题Which statement describes the effect on an index， when the indexed column for the rows is updatedin the base table（）A An update in a leaf row takes place.B The index becomes invalid after the update.C The leaf block containing the row to be updated is 

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：

As a result of performance analysis， you created an index on the prod_name column of the prod_det table， which contains about ten thousand rows. Later， you updated a product name in the table. How does this change affect the index？（）

• A、A leaf will be marked as invalid.
• B、An update in a leaf row takes place.
• C、The index will be updated automatically at commit.
• D、A leaf row in the index will be deleted and inserted.
• E、The index becomes invalid when you make any updates.

第3题：

Which statement describes the effect on an index， when the indexed column for the rows is updatedin the base table（）

• A、An update in a leaf row takes place.
• B、The index becomes invalid after the update.
• C、The leaf block containing the row to be updated is marked as invalid.
• D、A row in the leaf block of the index for the key value is logically deleted and a new leaf row is inserted

第4题：

Which two statements are true when row archival management is enabled?（）

• A、The ORA_ARCHIVE_STATE column visibility is controlled by the ROW ARCHIVAL VISIBILITY session parameter.
• B、The ORA_ARCHIVE_STATE column is updated manually or by a program that could reference activity tracking columns, to indicate that a row is no longer considered active.
• C、The ROW ARCHIVAL VISIBILITY session parameter defaults to active rows only.
• D、The ORA_ARCHIVE_STATE column is visible if referenced in the select list of a query.
• E、The ORA_ARCHIVE_STATE column is updated automatically by the Oracle Server based on activity tracking columns, to Indicate that a row is no longer considered active.

第5题：

You have created an Oracle 10g database named SALES， which will be used by an application named SalesOrders. Users of the SalesOrders application complain that application response time is slow when they generate reports. The SalesOrders application accesses a table that contains 10 million rows. You decide to create an index on this table using the NOLOGGING option so that the index creation process is completed in the least amount of time. Which of the following is NOT true about an index created with the NOLOGGING option？（）

• A、 The index can be changed from NOLOGGING to LOGGING
• B、 The index cannot be recovered even in the ARCHIVELOG mode.
• C、 The index can only be created if the base table is created with the NOLOGGING option.
• D、 The index can be recovered if you perform a backup after the CREATE INDEX statement.

第6题：

The SCOTT user has an index on the ITEM_DESC column of the ITEM table. As part of the year-ending task， SCOTT updates the ITEM_DESC column for most of the rows in the ITEM table. How does this change to the table affect the index？（）

• A、An update in a leaf row takes place.
• B、The index becomes invalid after the update.
• C、The leaf block containing the row to be updated is marked as invalid.
• D、A row in the leaf block of the index for the key value is deleted and inserted.

第7题：

You have altered a non-unique index to be invisible to determine if queries execute within an acceptable response time without using this index. Which two are possible if table updates are performed which affect the invisible index columns?（）

• A、The index remains invisible.
• B、The index is not updated by the DML statements on the indexed table.
• C、The index automatically becomes visible in order to have it updated by DML on the table.
• D、The index becomes unusable but the table is updated by the DML.
• E、The index is updated by the DML on the table.

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第13题：

Which two statements are true regarding B-tree indexs（）

• A、The leaf blocks in the index are doubly linked.
• B、The leaf node stores a bitmap for each key value.
• C、The rows with NULL value in key columns also have entries in the index.
• D、The deletion of a row from the table causes a logical deletion in index leaf block and the space becomesavailable for the new leaf entry

第14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15题：

User Scott has updated the salary of one of the employees in the EMPLOYEES table and has not committed the transaction. What are the two types of locks that this scenario would lead to？（）

• A、null lock on the row being updated
• B、null lock on the table containing the row
• C、ROW SHARE lock for the row being updated
• D、ROW EXCLUSIVE lock for the row being updated
• E、shared row-exclusive lock for the row being updated
• F、a shareable table lock for the table containing the row
• G、exclusive table-level lock for the table containing the row

第16题：

You work as a database administrator for Certkiller .com. As a result of performance analysis， you created an index on theprod_namecolumn of the  Certkiller prodtable， which contains about ten thousand rows. Later， you updated a product name in the table.  How does this change affect the index？（）

• A、A leaf will be marked as invalid.
• B、An update in a leaf row takes place.
• C、The index will be updated automatically at commit.
• D、A leaf row in the index will be deleted and inserted.
• E、The index becomes invalid when you make any updates

第17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18题：

Which two statements are true regarding B-tree index（）

• A、The leaf blocks in the index are doubly linked.
• B、The leaf node stores a bitmap for each key value.
• C、The rows with NULL value in key columns also have entries in the index.
• D、The deletion of a row from the table causes a logical deletion in index leaf block and the space becomes available for the new leaf entry.

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