Online Access Free 1z0-064 Practice Test

You want to enable the Database Smart Flash Cache feature on your database. For this purpose, you configure two flash devices: /dev/sdj and /dev/sdk, with sizes of 64 GB and 32 GB, respectively.
Examine the parameters set for your database instance:

How would you make sure that the database uses these devices for Database Smart Flash Cache?

• A.by disabling Automatic Memory Management, setting SGA_TARGET to 96G, and setting the required memory that you want to set for SGA
• B.by setting the value of the DB_FLASH_CACHE_SIZE parameter to 8G
• C.by setting the DB_FLASH_CACHE_SIZE parameter to 86G and the MEMORY_TARGET parameter to 112G
• D.by configuring the DB_FLASH_CACHE_SIZE parameter and making sure that all flash devices are of the same size
• E.by setting the value of the DB_FLASH_CACHE_SIZE parameter to 64G, 32G

Which three statements are true about the interpretation of an execution plan? (Choose three.)

• A.An INDEX UNIQUE SCAN in the Operation column always implies that only one row will be returned.
• B.The ROWS column indicates the cardinality of each operation and is always calculated by dividing the total number of rows in the table by the number of distinct values in the column used in the WHERE clause predicate.
• C.A TABLE ACCESS FULL in the Operation column for a query with a WHERE clause occurs only if no index exists for the filter column.
• D.A HASH JOIN in the Operation column always implies that two tables are joined by using an equijoin.
• E.The cost of the entire plan is indicated by the line with Id 0 and always includes both I/O and CPU resources.

You are administering a database that supports an OLTP workload. CURSOR_SHARING is set to EXACT for the instance. An application is frequently executing almost identical queries that vary in literal values in the WHERE clause, causing a large number of hard parses to occur.
Which four statements would be true if you use bind variables for these queries? (Choose four.)

• A.Mutex contention in the library cache will be reduced.
• B.Hard parses will be reduced for the queries.
• C.The optimizer will use bind peeking and use the literal value to determine the execution plan for these queries.
• D.The optimizer will use bind peeking and subsequent execution of the queries will always generate the same plans irrespective of the cardinality.
• E.The optimizer will use one parent cursor and one child cursor for each SQL statement with different literal values.
• F.The optimizer will generate the same plan for all bind values if no histograms exist on the columns used in the WHERE clause of these queries.

You are administrating a database that supports an OLTP workload. A new application module is deployed that is shipped along with the SQL plan baselines for the SQL statements executed by the application. You load the SQL plan baselines to the SQL Management Base.
Examine the parameters:

Which two statements are true in this scenario?

• A.The SQL plan baselines are used but better execution plans may be found and can be evolved manually for the SQL statements.
• B.The SQL plan baselines are not used by the SQL statements if the optimizer statistics are stale.
• C.The SQL plan baselines are loaded but are not used until SQL profiles are generated for the SQL statements.
• D.The SQL plan baselines are used by the SQL statements and ensure that the best plan is used.

Which two statements are true about the interpretation of Buffer Cache Hit Ratio in the Instance Efficiency Percentages section of an AWR report? (Choose two.)

• A.A high value indicates that the buffer cache is adequately sized for the current workload.
• B.A low hit ratio indicates that a KEEP buffer pool should be configured based on the size of the largest object accessed in the buffer cache.
• C.A high hit ratio may indicate that repeated scanning of the same large table or index is being performed.
• D.Poor hit ratios indicate that a large number of indexed lookups or small table scans are being performed.
• E.A low hit ratio does not necessarily imply that increasing the size of the buffer cache will improve performance.