EVISWANG的博客

怎么在不改变应用的情况下提升数据库的性能至百倍以上？如何在保证实现性能的同时还要保证易于使用、经济高效、不限规模、不限平台等需求呢？  以往，关系型数据库主要以行的形式进行存储，而近年来，列式数据库则成为了用户们津津乐道的产品。不管是行式数据库还是列式数据库，其实都是适用于不同的应用场景。比如SAP的行式数据库就更适用于电子商务应用，而列式存储则适用于分析应用。  Or

SQL> l  1  select s.event, count(s.event)  2   from  v$session s, v$process p  3  where s.PADDR = p.ADDR  4  group by s.event  5* order by 2 descSQL> EVENT                                ...

一.问题描述      在Hadoop集群的一个节点上用sqoop  import 从Oracle 取数据总报如下错误：17/12/28 19:16:48 INFO mapreduce.Job: Task Id : attempt_1512535288105_6822_m_000000_0, Status : FAILEDError: java.lang.RuntimeExceptio

[oracle@DW--cognos-1-10 admin]$ sqlplus cognos/SQL*Plus: Release 11.2.0.4.0 Production on Mon Nov 20 10:21:25 2017Copyright (c) 1982, 2013, Oracle.  All rights reserved.ERROR:ORA-00257: archiv

二. 恢复步骤：1. 参数文件恢复[oracle@localhost ~]$ rman target /Recovery Manager: Release 11.2.0.4.0 - Production on Tue Sep 5 05:50:45 2017Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights

一. 问题描述：DG搭建后之后发现备库无法打开SQL> alter database open read only;alter database open read only*ERROR at line 1:ORA-00221: error on write to control fileORA-00206: error in writing (block 17, #

em12c-> /home/oracle/em12c_middle/oms/bin/emctl start omsOracle Enterprise Manager Cloud Control 12c Release 3  Copyright (c) 1996, 2013 Oracle Corporation.  All rights reserved.Starting Oracle

Thu Jan 21 22:00:55 2016Errors in file /u01/PROD/oracle/diag/rdbms/prod/PROD1/trace/PROD1_j000_38573.trc:ORA-16957: SQL Analyze time limit interruptThu Jan 21 22:01:11 2016Errors in file /u01/

Thu Nov 19 01:13:49 2015ORA-00060:Deadlock detected. More info infile/u01/oracle/diag/rdbms/appserv/appserv/trace/appserv_ora_20577.trc.去查看相应的trace文件appserv_ora_20577.trc的死锁信息PS:相应的trc文件

Fri Dec 18 19:46:49 2015WARNING: Heavy swapping observed on system in last 5 mins.pct of memory swapped in [2.14%] pct of memory swapped out [0.08%].Please make sure there is no memory pressure

SPOOL ASM.HTML SET MARKUP HTML ON set echo on set pagesize 200 alter session set nls_date_format='DD-MON-YYYY HH24:MI:SS'; select 'THIS ASM REPORT WAS GENERATED AT: ==> ' , sysdate " " from dual;

SQL>drop diskgroup DATAGRP1 including contents;[DBT-30012] Dropping disk group DATAGRP1 failed.ORA-15039: diskgroup not droppedORA-15027: active use of diskgroup "DATAGRP1" precludes its dismou...