Free Oracle 1z1-064 Exam Dumps Questions & Answers

Users complain about increased response time for queries in your production database that supports an OLTP workload. On investigation, you notice a large number of db file scattered read, latch: cache buffers lru chain, and latch: cache buffers chains wait events:
Identify three possible reasons for the increased response time. (Choose three.)

• A.  the shared pool is inadequately sized
• B.  queries not using indexes and performing full table scans
• C.  queries repeatedly fetching blocks that are not in the database buffer cache
• D.  repeated simultaneous access to a block or small number of blocks
• E.  too many sort operations being performed
• F.  cursors are closed explicitly after each execution

Examine the Time Model Statistics section of an AWR report:

Which two inferences can be definitely derived from this section? (Choose two.)

• A.  The available CPU resources were not utilized to their maximum capacity.
• B.  All sequence numbers used during this AWR time interval were cached.
• C.  New child cursors were created because of new bind values or usage of literal values as well as different bind types or sizes.
• D.  A large number of connected user sessions were idle.
• E.  The DB CPU time was not spent exclusively for processing SQL statements.

You have been asked to assess if using column store compression (previously known as hybrid columnar compression or HCC) would help improve the performance of queries on some large tables.
Which three aspects should you consider before you choose this compression method? (Choose three.)

• A.  Check whether the table has LOB columns as it will minimize I/O for the queries.
• B.  Check whether the table blocks are sparsely populated as this will defragment the blocks.
• C.  Check whether the table is frequently updated because it will have overhead for insert and update operations.
• D.  Check whether the table is frequently queried using full table scans as column store compression only minimizes I/O during full table scans.
• E.  Check whether direct path load operations are used to insert rows in the table.

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

• A.  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.
• B.  The cost of the entire plan is indicated by the line with Id 0 and always includes both I/O and CPU resources.
• C.  An INDEX UNIQUE SCAN in the Operation column always implies that only one row will be returned.
• D.  A HASH JOIN in the Operation column always implies that two tables are joined by using an equijoin.
• E.  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.

You are administering a database that supports an OLTP workload. The CURSOR_SHARING parameter is set to EXACT for the instance. The performance of queries issued by one of the modules has degraded. The queries executed by the module are almost identical in syntax. To investigate, you analyze the latest AWR report and find a large number of latch:shared pool wait events and also a high percentage of the hard parse elapsed time.
Which two can be reasons for this? (Choose two.)

• A.  Bind variables are not used for similar queries, causing hard parses.
• B.  The CURSOR_SHARING parameter is set to EXACT, which does not allow similar queries to share a cursor.
• C.  The I/O performance is slow.
• D.  Repeated access to a small number of blocks.
• E.  Excessive time is spent on finding cached cursors in the library cache.