单选题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.()A3,2,1,4B2,3,4,1C4,1,3,2D3,2,4,1

单选题
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


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You executed the following commands: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.

You need to produce a report for mailing labels for all customers. The mailing label must have only the customer name and address. The CUSTOMERS table has these columns:CUST_ID NUMBER(4) NOT NULLCUST_NAME VARCHAR2(100) NOT NULLCUST_ADDRESS VARCHAR2(150)CUST_PHONE VARCHAR2(20)Which SELECT statement accomplishes this task?()A. SELECT* FROM customers;B. SELECT name, address FROM customers;C. SELECT id, name, address, phone FROM customers;D. SELECT cust_name, cust_address FROM customers;E. SELECT cust_id, cust_name, cust_address, cust_phone FROM customers;

Examine the following command that is executed for the TRANSPORT table in the SH schema:Which statement describes the significance of this command?() A. It collects statistics into the pending area in the data dictionaryB. It creates a virtual hidden column in the CUSTOMERS_OBE tableC. It collects statistics with AUTO_SAMPLE_SIZE for ESTIMATE_PERCENTD. It creates a histogram to hold skewed information about the data in the columns

Youexecutedthefollowingcommands:SQLALTERSESSIONSETOPTIMIZER_USE_PENDING_STATISTICS=false;SQLEXECUTEDBMS_STATS.SET_TABLE_PREFS(’SH’,’CUSTOMERS’,’PUBLISH’,’false’);SQLEXECUTEDBMS_STATS.GATHER_TABLE_STATS(’SH’,’CUSTOMERS’);WhichstatementiscorrectregardingtheabovestatisticscollectionontheSH.CUSTOMERStableintheabovesession?()A.Thestatisticsarestoredinthependingstatisticstableinthedatadictionary.B.Thestatisticsaretreatedasthecurrentstatisticsbytheoptimizerforallsessions.C.Thestatisticsaretreatedasthecurrentstatisticsbytheoptimizerforthecurrentsessionsonly.D.Thestatisticsaretemporaryandusedbytheoptimizerforallsessionsuntilthissessionterminates.

Which three statements are true about SQL plan directives?() A. They are tied to a specific statement or SQL id.B. They instruct the maintenance job to collect missing statistics or perform dynamic sampling to generate a more optimal plan.C. They are used to gather only missing statistics.D. They are created for a query expression where statistics are missing or the cardinality estimates by the optimizer are incorrect.E. They instruct the optimizer to create only column group statistics.F. Improve plan accuracy by persisting both compilation and execution statistics in the SYSAUX tablespace.

You need to generate a list of all customer last names with their credit limits from the CUSTOMERS table. Those customers who do not have a credit limit should appear last in the list. Which two queries would achieve the required result?()A、SELECT cust_last_name, cust_credit_limit FROM customers ORDER BY cust_credit_limit DESCB、SELECT cust_last_name, cust_credit_limit FROM customers ORDER BY cust_credit_limitC、SELECT cust_last_name, cust_credit_limit FROM customers ORDER BY cust_credit_limit NULLS LASTD、SELECT cust_last_name, cust_credit_limit FROM customers ORDER BY cust_last_name, cust_credit_limit NULLSLAST

The CUSTOMERS table has these columns: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL STREET_ADDRESS VARCHAR2(150) CITY_ADDRESS VARCHAR2(50) STATE_ADDRESS VARCHAR2(50) PROVINCE_ADDRESS VARCHAR2(50) COUNTRY_ADDRESS VARCHAR2(50) POSTAL_CODE VARCHAR2(12) CUSTOMER_PHONE VARCHAR2(20) The CUSTOMER_ID column is the primary key for the table. Which two statements find the number of customers? () A、SELECT TOTAL(*) FROM customer;B、SELECT COUNT(*) FROM customer;C、SELECT TOTAL(customer_id) FROM customer;D、SELECT COUNT(customer_id) FROM customer;E、SELECT COUNT(customers) FROM customer;F、SELECT TOTAL(customer_name) FROM customer;

Examine the command: SQL DBMS_STATS.SET_TABLE_PREFS(’SH’, ’CUSTOMERS’, ’PUBLISH’, ’false’);  Which statementdescribes 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

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、3,2,1,4B、2,3,4,1C、4,1,3,2D、3,2,4,1

Examine the description of the CUSTOMERS table: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL STREET_ADDRESS VARCHAR2(150) CITY_ADDRESS VARCHAR2(50) STATE_ADDRESS VARCHAR2(50) PROVINCE_ADDRESS VARCHAR2(50) COUNTRY_ADDRESS VARCHAR2(50) POSTAL_CODE VARCHAR2(12) CUSTOMER_PHONE VARCHAR2(20) The CUSTOMER_ID column is the primary key for the table. Which statement returns the city address and the number of customers in the cities Los Angeles or San Francisco?()A、SELECT city_address, COUNT(*) FROM customers WHERE city_address IN ('Los Angeles', 'San Francisco');B、SELECT city_address, COUNT(*) FROM customers WHERE city_address IN ('Los Angeles', 'San Francisco') GROUP BY city_address;C、SELECT city_address, COUNT(customer_id) FROM customers WHERE city_address IN ('Los Angeles', 'San Francisco') GROUP BY city_address, customer_id;D、SELECT city_address, COUNT(customer_id) FROM customers GROUP BY city_address IN ('Los Angeles', 'San Francisco');

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.

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.

Consider the following statement:   SQL EXECUTE DBMS_STATS.GATHER_SHEMA_STATS (-  2 ownname = ‘OE’, -  3 estimate_percent = DBMS_STATS.AUTO_SAMPLE_SIZE, -  4 method opt = ‘for all columns size AUTO’);   What is the effect of ‘for all columns size AUTO’ of the METHOD_OPT option?()A、The Oracle server creates a new histogram based on existing histogram definitions for all table, column, and index statistics for the OE schema. B、The Oracle server creates a histogram based on data distribution regardless of how the application uses the column/s for all table, column, and index statistics for the OE schema.C、The Oracle server creates a histogram based on data and application usage of the column/s for all table, column, and index statistics for the OE schema. D、The Oracle server creates a histogram based on application usage, regardless of data distribution, for all table, column, and index statistics for the OE schema.

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.

单选题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.()A3,2,1,4B2,3,4,1C4,1,3,2D3,2,4,1

单选题Examine the description of the CUSTOMERS table: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL STREET_ADDRESS VARCHAR2(150) CITY_ADDRESS VARCHAR2(50) STATE_ADDRESS VARCHAR2(50) PROVINCE_ADDRESS VARCHAR2(50) COUNTRY_ADDRESS VARCHAR2(50) POSTAL_CODE VARCHAR2(12) CUSTOMER_PHONE VARCHAR2(20) The CUSTOMER_ID column is the primary key for the table. Which statement returns the city address and the number of customers in the cities Los Angeles or San Francisco?()ASELECT city_address, COUNT(*) FROM customers WHERE city_address IN ('Los Angeles', 'San Francisco');BSELECT city_address, COUNT(*) FROM customers WHERE city_address IN ('Los Angeles', 'San Francisco') GROUP BY city_address;CSELECT city_address, COUNT(customer_id) FROM customers WHERE city_address IN ('Los Angeles', 'San Francisco') GROUP BY city_address, customer_id;DSELECT city_address, COUNT(customer_id) FROM customers GROUP BY city_address IN ('Los Angeles', 'San Francisco');

单选题You need to produce a report for mailing labels for all customers. The mailing label must have only the customer name and address. The CUSTOMERS table has these columns: CUST_ID NUMBER(4) NOT NULL CUST_NAME VARCHAR2(100) NOT NULL CUST_ADDRESS VARCHAR2(150) CUST_PHONE VARCHAR2(20) Which SELECT statement accomplishes this task?()ASELECT* FROM customers;BSELECT name, address FROM customers;CSELECT id, name, address, phone FROM customers;DSELECT cust_name, cust_address FROM customers;ESELECT cust_id, cust_name, cust_address, cust_phone FROM customers;

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 gathered.BStatistics collection is not done for the CUSTOMERS table when database stats are gathered.CAny existing statistics for the CUSTOMERS table are still available to the optimizer at parse time.DStatistics gathered on the CUSTOMERS table when schema stats are gathered are stored as pending statistics.EStatistics gathered on the CUSTOMERS table when database stats are gathered are stored as pending statistics.

多选题Which three statements are true about SQL plan directives?()AThey are tied to a specific statement or SQL id.BThey instruct the maintenance job to collect missing statistics or perform dynamic sampling to generate a more optimal plan.CThey are used to gather only missing statistics.DThey are created for a query expression where statistics are missing or the cardinality estimates by the optimizer are incorrect.EThey instruct the optimizer to create only column group statistics.FImprove plan accuracy by persisting both compilation and execution statistics in the SYSAUX tablespace.

单选题Examine the command: SQL DBMS_STATS.SET_TABLE_PREFS(’SH’, ’CUSTOMERS’, ’PUBLISH’, ’false’);  Which statementdescribes the effect of the above command()AAutomatic statistics collection is stopped for the CUSTOMERS table.BStatistics for the CUSTOMERS table are locked and cannot be overwritten.CExisting statistics for the CUSTOMERS table become unusable for the query optimizer.DSubsequently, statistics gathered on the CUSTOMERS table are stored as pending statistics

单选题Examine the command:  SQL DBMS_STATS.SET_TABLE_PREFS(’SH’, ’CUSTOMERS’, ’PUBLISH’, ’false’); Which statement describes the effect of the above command()AAutomatic statistics collection is stopped for the CUSTOMERS table.BStatistics for the CUSTOMERS table are locked and cannot be overwritten.CExisting statistics for the CUSTOMERS table become unusable for the query optimizer.DSubsequently, statistics gathered on the CUSTOMERS table are stored as pending statistics.

单选题You executed the following commands: 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.

单选题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.()A3,2,1,4B2,3,4,1C4,1,3,2D3,2,4,1

单选题Consider the following statement:   SQL EXECUTE DBMS_STATS.GATHER_SHEMA_STATS (-  2 ownname = ‘OE’, -  3 estimate_percent = DBMS_STATS.AUTO_SAMPLE_SIZE, -  4 method opt = ‘for all columns size AUTO’);   What is the effect of ‘for all columns size AUTO’ of the METHOD_OPT option?()AThe Oracle server creates a new histogram based on existing histogram definitions for all table, column, and index statistics for the OE schema. BThe Oracle server creates a histogram based on data distribution regardless of how the application uses the column/s for all table, column, and index statistics for the OE schema.CThe Oracle server creates a histogram based on data and application usage of the column/s for all table, column, and index statistics for the OE schema. DThe Oracle server creates a histogram based on application usage, regardless of data distribution, for all table, column, and index statistics for the OE schema.

单选题You have a range-partitioned table in your database. Each partition in the table contains the sales data for a quarter.  The partition related to the current quarter is modified frequently and other partitions undergo fewer data manipulations. The preferences for the table are set to their default values. You collect statistics for the table using the following command in regular intervals: SQL EXECUTE  DBMS_STATS.GATHER_TABLE_STATS(’SH’,’SALES’,GRANULARITY=’GLOBAL’);   You need statistics to be collected more quickly.  What can you do to achieve this?()A Set DYNAMIC_SAMPLING to level 4B Set the STATISTICS_LEVEL parameter to BASICC Set the INCREMENTAL value to TRUE for the partition tableD Increase the value of STALE_PERCENT for the partition table

单选题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.

单选题Exhibit: Examine the data in the EMPLOYEES table. Examine the subquery: SELECT last_name FROM employees WHERE salary IN (SELECT MAX(salary) FROM employees GROUP BY department_id); Which statement is true?()A The SELECT statement is syntactically accurate.B The SELECT statement does not work because there is no HAVING clause.C The SELECT statement does not work because the column specified in the GROUP BY clause is not in the SELECT list.D The SELECT statement does not work because the GROUP BY clause should be in the main query and not in the subquery.

单选题You need to produce a report for mailing labels for all customers. The mailing label must have only the customer name and address. The CUSTOMERS table has these columns: Which SELECT statement accomplishes this task?()A SELECT* FROM customers;B SELECT name, address FROM customers;C SELECT id, name, address, phone FROM customers;D SELECT cust_name, cust_address FROM customers;E SELECT cust_id, cust_name, cust_address, cust_phone FROM customers;