Performance Tuning And Diagnostics

When reviewing an AWR report, you notice a high value for 'db time'. What does this indicate?

Which THREE factors influence the optimizer's choice of an execution plan?

You are a DBA for an Oracle Database 23ai instance. A developer reports that a specific SQL statement is performing poorly. You want to gather detailed execution statistics for this single statement to diagnose the issue. Which two methods can provide the actual execution plan and runtime statistics for this statement? (Choose two.)

Which TWO views can be used to monitor current session performance?

When running the SQL Tuning Advisor, what does the 'Accept' action do?

Which background process is responsible for capturing AWR snapshots?

You are an Oracle Database 23ai administrator. A developer complains that a query against a table with a recently added column is returning stale results. You suspect that the optimizer's statistics are outdated. Which task should you perform to refresh the statistics for this table?

You are the DBA for an Oracle Database 23ai instance. Users report that a particular application module is slow. You query V$ACTIVE_SESSION_HISTORY and see a high number of samples for the wait event 'log file sync'. You want to determine which sessions and SQL statements are contributing most to this wait. Which of the following would you use to find the top sessions and SQL_IDs associated with 'log file sync'?

You are an Oracle Database 23ai administrator. A batch job that performs many small random reads on a large table is experiencing high 'db file sequential read' wait times. The table is stored in a tablespace with a block size of 8 KB. You suspect that the storage subsystem is the bottleneck. Which action would best confirm whether the wait time is due to slow disk I/O?

Which of these is the most effective way to address performance issues caused by suboptimal plans?

Which parameter controls the frequency of AWR snapshot collection?

When using the SQL Tuning Advisor to analyze a SQL statement, which THREE types of recommendations can it provide to improve performance?

Which TWO components are essential for the operation of the Automatic Database Diagnostic Monitor (ADDM)?

Which THREE items are required for the Automatic SQL Plan Management to effectively stabilize plans?

You are the lead DBA for a busy online transaction processing (OLTP) database. Users report that a critical order-entry application has become slow. You run a query against V$SYSTEM_EVENT and notice that the 'log file sync' wait event has the highest total time waited. Which action should you take to address this issue?

You are an Oracle Database 23ai administrator. A user reports that a specific SQL query is running slowly. You want to see the execution plan that the optimizer actually used for the most recent execution of that query. Which dynamic performance view should you query?

You have a high volume of parse time in your database. What could be the cause?

What is the purpose of the 'ASH' report?

You have a query that is being incorrectly optimized because the statistics are not representative of the actual data distribution. What is the best method to handle this without changing the global statistics?

Which feature allows you to capture SQL statements from the cursor cache and load them into a SQL Tuning Set?

You are analyzing an AWR report for an Oracle Database 23ai instance. You notice that the 'DB Time' is significantly higher than the 'Elapsed Time' for the snapshot interval. What does this indicate?

What does the 'Elapsed Time' in a SQL statement represent?

A production database experiences a sudden performance degradation. You want to analyze the last 10 minutes of activity to pinpoint blocked sessions. Which approach is best?

Which THREE of the following are components of the Oracle performance tuning lifecycle?

You need to capture a specific set of SQL statements that are causing high CPU usage for later tuning. Which tool allows you to group these statements and transport them across different database environments?

A DBA is analyzing an AWR report for an Oracle Database 23ai instance and notices a high number of 'enq: TX - row lock contention' waits. Which two actions should the DBA take to diagnose and resolve this issue? (Choose two.)

You are an Oracle Database 23ai administrator. Users report that a critical order-entry form intermittently stalls for several seconds when submitting a row. You run an AWR report for the busy period and notice a high average 'row lock wait time' and a significant number of 'enq: TX - row lock contention' waits. Which action should you take first to diagnose the issue?

You are an Oracle Database 23ai administrator. A developer complains that a query joining two large tables is spilling to disk, and the session shows high 'direct path write temp' waits. The database uses Automatic Shared Memory Management (ASMM) and Automatic PGA Memory Management. Which action should you take to allow the query to complete without disk spills?

What does the 'SQL ID' in an Oracle database represent?

You notice that a specific query is performing very slowly due to excessive 'direct path read' waits. What is the most likely cause?

Which procedure in the DBMS_SPM package is used to evolve a SQL plan baseline?

You are performing a SQL tuning exercise. How do you create a SQL Tuning Set (STS) to be used as input for the SQL Tuning Advisor?

You are tuning a data warehouse query that performs a large hash join. The query is spilling to disk, and you want to determine if increasing the PGA_AGGREGATE_TARGET would help. Which of the following dynamic performance views would you query to see the current PGA memory usage and the number of multi-pass executions?

You are diagnosing a performance issue where a specific SQL statement is consuming excessive CPU. You have identified the SQL_ID and want to gather detailed execution statistics for this statement to understand its behavior. Which two methods can you use to obtain execution statistics for this SQL statement? (Choose two.)

You are the lead DBA for an Oracle Database 23ai production system. Users report that a critical order-entry application becomes unresponsive for several seconds every few minutes. While monitoring, you notice a significant number of 'log file sync' wait events in V$SYSTEM_EVENT. Which action is most likely to reduce this contention?

You are analyzing a performance degradation in a data warehouse. The AWR report shows a high number of 'cell single block physical read' waits on Exadata. You suspect that the storage index is not being used effectively for a particular query. Which action should you take to improve the effectiveness of the storage index for this query?

You are analyzing a performance issue in your Oracle 23ai database. You suspect that a specific SQL statement is performing poorly due to a suboptimal execution plan. You want to capture the actual execution plan and runtime statistics for this statement while it is executing. Which tool should you use to achieve this with minimal overhead?

You need to identify the top SQL statements consuming the most CPU resources in an Oracle 23ai database over the last hour. Which tool provides the most direct analysis of this performance issue?

You are investigating a performance issue where a batch job that inserts millions of rows into a table with a unique index is running slowly. You notice a high number of 'enq: TX - index contention' waits. Which action is most likely to reduce this contention without compromising data integrity?

You are seeing 'enq: TX - row lock contention' in your performance reports. What does this mean?

You are analyzing an AWR report and notice a high value for 'db file scattered read'. What is the most likely cause of this wait event?

Which TWO of these are common sources of performance degradation?

Which of the following is true regarding SQL Plan Baselines?

In which view can you find information about the current SQL Plan Baselines?

You observe a significant performance regression after a database upgrade. You suspect that the optimizer has chosen a suboptimal execution plan. Which component of SQL Plan Management should you use to ensure the database only uses known, verified execution plans?

You are managing an Oracle Database 23ai instance. A critical application query is performing poorly. You have identified the SQL ID and want to capture a detailed execution plan with runtime statistics for a specific execution. The query is currently running and has been for several minutes. Which action should you take to get the most detailed diagnostic information?

You are diagnosing a performance issue in an Oracle Database 23ai instance. You suspect that the issue is related to the optimizer's cardinality estimates. You want to gather additional information to confirm your suspicion. Which two of the following would provide you with the optimizer's estimated cardinality and the actual cardinality for each step of an execution plan? (Choose two.)

You have a query that is performing poorly due to a stale execution plan. You want to lock the current optimal plan to prevent the optimizer from changing it during subsequent runs. What should you do?

Which TWO types of reports are most useful for diagnosing long-term database performance trends?

Which report provides a summary of SQL statements that have the highest 'Elapsed Time'?

An administrator has been tasked with reducing the overhead of AWR snapshot collection. What is the most effective way to modify the snapshot interval?

How can you view the recommendations made by the Automatic Database Diagnostic Monitor (ADDM)?

An administrator needs to identify the top wait events causing performance degradation in the database over the last hour. Which tool provides the most granular, session-level view of these wait events?

Which THREE actions can you take to improve execution plan stability?

When using SQL Tuning Advisor, what is a 'SQL Tuning Set' (STS)?

Which view displays the current settings for the AWR retention period?

You are tuning a complex SQL statement. You want to see the execution plan that the optimizer is currently choosing. Which dynamic performance view is most useful?

To improve performance, you suspect an index is missing. Which advisor should you invoke to get recommendations for new indexes?

The Automatic SQL Plan Management (ASPM) feature is enabled. A new execution plan is identified for a high-load query that performs better during testing. How does the database verify this plan before evolving the baseline?

Which TWO methods can be used to tune SQL statements?

You are tuning a query that is performing poorly due to high 'buffer busy waits'. What is the likely cause?

What is the primary benefit of using a SQL Profile?

Which THREE types of information are captured in an AWR snapshot?

What is the primary function of ADDM in Oracle Database 23ai?

What is the result of setting STATISTICS_LEVEL to 'BASIC'?

You are managing an Oracle Database 23ai instance where a specific SQL statement is consuming excessive CPU. You want to identify the top SQL statements by CPU usage in real time. Which dynamic performance view should you query?

You are analyzing a query with the SQL Tuning Advisor. The advisor recommends an 'SQL Profile'. What does the profile actually do?

A DBA is troubleshooting a performance issue in Oracle Database 23ai. A query that previously used an index full scan now performs a full table scan. The DBA suspects that the optimizer's statistics are stale. Which action should the DBA take to confirm this suspicion?

You are investigating high CPU utilization in the database. Which view provides the top SQL statements currently in memory based on CPU usage?