|| id); -- Wait till the job is done. This ensures the hadoop job is completed loop select count(*) into cnt from DBA_SCHEDULER_JOBS where job_name = 'EXTSCRIPT'||id; dbms_output.put_line('Scheduler 数据 select sum(c) into cnt from ( select enqueued_msgs - dequeued_msgs c from gv$persistent_queues where queue_name = 'HADOOP_MR_QUEUE' union all select num_msgs+spill_msgs num_msgs+spill_msgs c from gv$buffered_queues where queue_name = 'HADOOP_MR_QUEUE' union all select 0 c from dual ); if (cnt = 0) then -- Queue is done. stop it. DBMS_AQADM.STOP_QUEUE ('HADOOP_MR_QUEUE');

'World!')"); con.commit(); PreparedStatement statement = con.prepareStatement("select * from test"); ResultSet rs = statement.executeQuery(); while (rs.next())

询 • 使用MapReduce来实现 • 比Hive访问HDFS慢3~5倍 IDH引入了Interactive Hive over HBase • 完全的Hive支持：常用功能（select, group-by等）用HBase coprocessor 实现，其余功能用MapReduce实现，无缝连接 • 去除了MapReduce的overhead，大大减少了数据传输 • 性能有3X~10X的提升

* 语法：Values、CTE、SEMIJOIN、FROM 倒装、 Subquery Operations、Set Operations(UNION /INTERSECT /MINUS)、SELECT TRANSFORM 、User Alibaba Cloud MaxCompute 解决方案 13 Defined Type、GROUPING SET(CUBE/rollup/GROUPING