什么是ETL？
什么是ETL？
相关考题：
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?（）A. Examine the Active Session History (ASH) reports for the time period of the ETL or batch reporting runs.B. Enable SQL tracing for the queries in the ETL and batch reporting queries and gather diagnostic data from the trace file.C. Enable real-time SQL monitoring for ETL jobs and gather diagnostic data from the V$SQL_MONITOR view.D. 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.
Name the three fundamental fact grains and describe an ETL approach for each.简述三种基本事实表，并说明ETL的过程中如何处理它们。
What steps do you take to determine the bottleneck of a slow running ETL process?如果ETL进程运行较慢，需要分哪几步去找到ETL系统的瓶颈问题。
修改dmetl.ini控制文件的哪个参数可控制ETL引擎是否随机启动（）A、METADATA_TYPEB、ENGINE_WORKER_COUNTC、START_ETL_ENGINED、SERVICE_TYPE
单选题Hadoop生态系统中，被作为ETL使用的软件是（）ASqoopBBigtopCAutoconfDOracle