You upgraded from a previous Oracle database version to Oracle Database version to Oracle Database12c. Your database supports a mixed workload. During the day, lots of insert, update, and deleteoperations are performed. At night, Extract, Transform, Load (ETL) and batch reporting jobs are run. The ETL jobs perform certain database operations using two or more concurrent sessions.After the upgrade, you notice that the performance of ETL jobs has degraded. To ascertain the cause ofperformance degradation, you want to collect basic statistics such as the level of parallelism, totaldatabase time, and the number of I/O requests for the ETL jobs. How do you accomplish this?（） Examine the Active Session History (ASH) reports for the time period of the ETL or batch reporting runs.。 Enable SQL tracing for the queries in the ETL and batch reporting queries and gather diagnostic data from the trace file.。 Enable real-time SQL monitoring for ETL jobs and gather diagnostic data from the V$SQL_MONITOR view.。 Enable real-time database operation monitoring using the DBMS_SQL_MONITOR.BEGIN_OPERATION function, and then use the DBMS_SQL_MONITOR.REPORT_SQL_MONITOR function to view the required information.。
特征与基本形
Identify four uses of the Oracle Scheduler.（） enables Oracle database to schedule which processes execute on which processors in a multiple CPU environment。 enables Oracle database to do patches according to a DBA-defined schedule。 enables you to schedule the execution of jobs based on time。 enables you to execute jobs in a clustered environment。 enables you to periodically execute operating systemscript files located on the same server as the database。 enables you to create a job that makes use of saved programs and schedules。 enables you to automate the management of the jobs that are created using the DBMS_JOB package。
国家突发公共事件总体应急预案中提出突发公共事件主要包括四类，分别为自然灾害、事故灾难、公共卫生事件、社会安全事件四类，其中自然灾害不包括以下哪项（） 水旱灾害。 地震灾害。 经济灾害。 气象灾害。
One of the user sessions was terminated abnormally in the middle of a transaction. What does Oracle database do to recover it？（） uses undo data for roll forward。 uses Flashback Log for recovery。 uses online redo logs to roll back。 uses undo data to roll back the transaction。 uses Recovery Manager （RMAN） to roll back。 uses the System Monitor （SMON） background process to perform instance recovery。
变压站（所）内铝金属性的设备接头过热后其颜色会变为（）。
