摘要:
explain plan for select stddev(DEPTNO) from TEST_EMP; SELECT plan_table_output FROM table(dbms_xplan.display('plan_table')); select * from table(dbms_ 阅读全文
摘要:
(1)去/etc下面的hostname修改机器的主机名,之后在/etc/hosts下面将每台机器的ip和名字写进去,如下: 192.168.112.128 master192.168.112.129 slave1192.168.112.130 slave2 (2)确认机器上是否安装了ssh,若未安装 阅读全文
摘要:
最近使用eclipse操作hdfs遇到如下报错 log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).log4j:WARN Please ini 阅读全文