多选题Examine this command: SQL > exec DBMS_STATS.SET_TABLE_PREFS (‘SH’, ‘CUSTOMERS’, ‘PUBLISH’, ‘false’); Which three statements are true about the effect of this command?（）AStatistics collection is not done for the CUSTOMERS table when schema stats are gat

第1题：

You are working in an online transaction processing (OLTP) environment. You use the FLASHBACKTABLE command to flash back the CUSTOMERS table. Before executing the FLASHBACK TABLE command, the system change number (SCN) was 663571. After flashing back the CUSTOMERS table, you realize that the table is not in the correct state. Now, you need to reverse the effects of the FLASHBACK TABLE command. Which is the fastest and the most efficient option to reverse the effects of the FLASHBACK TABLE command?（）

• A、Restore the backup control file and open the database with RESETLOGS option.
• B、Perform point-in-time recovery because flashback cannot be performed again on this table
• C、Execute the FLASHBACK DATABASE statement to retrieve the CUSTOMERS table as it was at SCN 663571
• D、Execute another FLASHBACK TABLE statement to retrieve the CUSTOMERS table as it was at SCN 663571

第2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3题：

You want to capture column group usage and gather extended statistics for better cardinality estimates for the CUSTOMERS table in the SH schema. Examine the following steps: 1. Issue the SELECT DBMS_STATS.CREATE_EXTENDED_STATS (‘SH’, ‘CUSTOMERS’) FROM dual statement. 2. Execute the DBMS_STATS.SEED_COL_USAGE (null, ‘SH’, 500) procedure. 3. Execute the required queries on the CUSTOMERS table. 4. Issue the SELECT DBMS_STATS.REPORT_COL_USAGE (‘SH’, ‘CUSTOMERS’) FROM dual statement. Identify the correct sequence of steps.（）

• A、3，2，1，4
• B、2，3，4，1
• C、4，1，3，2
• D、3，2，4，1

第4题：

You execute the following commands to audit database activities: SQL > ALTER SYSTEM SET AUDIT_TRIAL=DB, EXTENDED SCOPE=SPFILE; SQL > AUDIT SELECT TABLE, INSERT TABLE, DELETE TABLE BY JOHN By SESSION WHENEVER SUCCESSFUL; Which statement is true about the audit record that generated when auditing after instance restarts?（）

• A、One audit record is created for every successful execution of a SELECT, INSERT OR DELETE command on a table, and contains the SQL text for the SQL Statements.
• B、One audit record is created for every successful execution of a SELECT, INSERT OR DELETE command, and contains the execution plan for the SQL statements.
• C、One audit record is created for the whole session if john successfully executes a SELECT, INSERT, or DELETE command, and contains the execution plan for the SQL statements.
• D、One audit record is created for the whole session if JOHN successfully executes a select command, and contains the SQL text and bind variables used.
• E、One audit record is created for the whole session if john successfully executes a SELECT, INSERT,or DELETE command on a table, and contains the execution plan, SQL text, and bind variables used.

第5题：

Examine this command: SQL > exec DBMS_STATS.SET_TABLE_PREFS (‘SH’, ‘CUSTOMERS’, ‘PUBLISH’, ‘false’); Which three statements are true about the effect of this command?（）

• A、Statistics collection is not done for the CUSTOMERS table when schema stats are gathered.
• B、Statistics collection is not done for the CUSTOMERS table when database stats are gathered.
• C、Any existing statistics for the CUSTOMERS table are still available to the optimizer at parse time.
• D、Statistics gathered on the CUSTOMERS table when schema stats are gathered are stored as pending statistics.
• E、Statistics gathered on the CUSTOMERS table when database stats are gathered are stored as pending statistics.

第6题：

You are working in an online transaction processing （OLTP） environment. You used the FLASHBACK TABLE command to flash back the CUSTOMERS table. Before executing the FLASHBACK TABLE command， the System Change Number （SCN） was 663571. After flashing back the CUSTOMERS table， you realize that the table is not in the correct state and the resultant changes are not what you had desired. So， you need to reverse the effects of the FLASHBACK TABLE command while ensuring that：  a） No other user data in the database is affected.  b） The operation takes the minimum possible time.  Which option would you choose？（）

• A、use the ROLLBACK command with SCN 663571
• B、perform Flashback Transaction Query with SCN 663571
• C、execute the FLASHBACK DATABASE statement to retrieve the CUSTOMERS table as it was at SCN 663571
• D、execute another FLASHBACK TABLE statement to retrieve the CUSTOMERS table as it was at SCN 663571

第7题：

Examine the command：  SQL> DBMS_STATS.SET_TABLE_PREFS（’SH’， ’CUSTOMERS’， ’PUBLISH’， ’false’）； Which statement describes the effect of the above command（）

• A、Automatic statistics collection is stopped for the CUSTOMERS table.
• B、Statistics for the CUSTOMERS table are locked and cannot be overwritten.
• C、Existing statistics for the CUSTOMERS table become unusable for the query optimizer.
• D、Subsequently， statistics gathered on the CUSTOMERS table are stored as pending statistics.

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第13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.

第14题：

You execute the following command in your Certkiller .com production database to change the width of the CUST_NAME column of the CUSTOMERS table： ALTER TABLE customers  MODIFY （cust_nameVARCHAR2 （40）） /  When you execute the command， it displays the following error message：  ERROR at line 1：  ORA-00054： resource busy and acquire with NOWAIT specified  What could be the reason for the error message？（）

• A、The database instance is not available.
• B、The ALTER TABLE command does not have WAIT option
• C、The table or a row in the table is currently locked by another user session.
• D、The database instance is busy processing other user sessions commands.
• E、The CUSTOMERS table has no long running query active at the time when this request is made.
• F、The server process executing the ALTER TABLE command is busy with another command execution

第15题：

You executed the following commands：   SQL> ALTER SESSION SET OPTIMIZER_USE_PENDING_STATISTICS = false； SQL> EXECUTE DBMS_STATS.SET_TABLE_PREFS（’SH’， ’CUSTOMERS’， ’PUBLISH’，’false’）； SQL> EXECUTE DBMS_STATS.GATHER_TABLE_STATS（’SH’， ’CUSTOMERS’）；   Which statement is correct regarding the above statistics collection on the SH.CUSTOMERS table in the above session？（）

• A、 The statistics are stored in the pending statistics table in the data dictionary.
• B、 The statistics are treated as the current statistics by the optimizer for all sessions.
• C、 The statistics are treated as the current statistics by the optimizer for the current sessions only.
• D、 The statistics are temporary and used by the optimizer for all sessions until this session terminates.

第16题：

Examine the commands executed in the following sequence：  1：SQL> CREATE ROLE mgrrole；  2：SQL> GRANT create user，select any table，connect，resource TO mgrrole；  3：SQL> GRANT select，update ON sh.sales TO mgrrole；  4：SQL> CREATE ROLE ceo IDENTIFIED BY boss；  5：SQL> GRANT mgrrole，drop any table，create any directory TO ceo；  6：SQL> GRANT ceo TO mgrrole；  Which statement is true about the above commands（）

• A、The commands execute successfully.
• B、Command 6 produces an error because of circular role grant.
• C、Command 5 produces an error because a role cannot be granted to another role.
• D、Command 3 produces an error because the MGRROLE role already contains system privileges.
• E、The table created by HR remains and HR still has the CREATE TABLE system privilege.
• F、The table created by HR remains and HR can grant the CREATE TABLE system privilege to other users.

第17题：

You execute this command to drop the ITEM table， which has the primary key referred in the ORDERS table：SQL> DROP TABLE scott.item CASCADE CONSTRAINTS PURGE；  Which two statements are true about theeffect of the command（）

• A、No flashback is possible to bring back the ITEM table.
• B、The ORDERS table is dropped along with the ITEM table.
• C、The dependent referential integrity constraints in the ORDERS table are disabled.
• D、The dependent referential integrity constraints in the ORDERS table are removed.
• E、The table definition of the ITEM table and associated indexes are placed in the recycle bin

第18题：

Examine the following statement that is used to modify the constraint on the SALES table： SQL> ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements are true regarding the above command（）

• A、The constraint remains valid.
• B、The index on the constraint is dropped.
• C、It allows the loading of data into the table using SQL*Loader.
• D、New data conforms to the constraint， but existing data is not checked
• E、It allows the data manipulation on the table using INSERT/UPDATE/DELETE SQL statements.

第19题：

Examine the following statement that is used to modify the primary key constraint on the SALES table： SQL> ALTER TABLE SALES MODIFY CONSTRAINT pk DISABLE VALIDATE； Which three statements aretrue regarding the above command（）

• A、The constraint remains valid.
• B、The index on the constraint is dropped.
• C、It allows the loading of data into the table using SQL *Loader.
• D、New data conforms to the constraint， but existing data is not checked.
• E、It allows the data manipulation on the table using INSERT/UPDATE/DELETE SQL statements.

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