know more about dbms_job fails

When job execution fails, the SNP processes attempts to rerun the job one minute later. If this run fails, another attempt is made in two minutes and another in four minutes. The job queue doubles the retry interval until it exceeds the normal execution interval..

about parallel

目前机器通常都是多core CPU,单个进程未开并行只会在一个core上运行,未完全发挥多core的特性,有时在统计查询,DML,DDL时需要开启并行提高效率