Ed Chen Logic

How to Resolve CRS-4995: The command 'Modify resource' is invalid in crsctl. Use srvctl for this command.

by Ed Chen
November 6, 2012May 23, 2022

CRS-4995 For Oracle 11g, we can modify the attribute of a resource like this: [grid@primary01 ~]$ crsctl modify resource ora.dbname.db -attr AUTO_START=always [grid@primary01 ~]$ crsctl… Read More »

How to Resolve ORA-16649 after a Fast-Start Failover

by Ed Chen
November 6, 2012January 12, 2021

After a fast-start failover, the broker will try to reinstate the standby database (former primary database) for sustaining data guard architecture. While reinstating, the broker… Read More »

How to Implement Fast-Start Failover 11g

by Ed Chen
November 5, 2012August 5, 2020

Before enabling fast-start failover in data guard broker, the only required precondition is enabling Flashback Database. But before enabling Flashback Database, you must enable Flash… Read More »

How to Failover to a Standby Database Manually and Rebuild Data Guard - By Example

by Ed Chen
November 4, 2012January 19, 2021

Since a fast-start failover (automatic failover) could become a false failover when the observer or the standby database cannot connect to the primary database within… Read More »

Restrictions on Adding a Datafile

by Ed Chen
November 3, 2012March 28, 2021

There are two major restrictions must be considered before you add a datafile to a tablespace. One is about the number limit of datafiles, the… Read More »

Srvctl Modify Database Startup Options

by Ed Chen
November 2, 2012November 9, 2022

Srvctl Start Database Mount Standby In some cases, you would like to change the default startup option of srvctl other than OPEN, for example, after… Read More »

How to Set Autocommit ON and OFF

by Ed Chen
November 1, 2012November 12, 2022

Implicit Commit In the default behavior, if session A wants to see session B's results, he must be waiting for session B to commit his… Read More »

How Oracle Enable Flashback Database

by Ed Chen
October 31, 2012August 29, 2021

Enabling Flashback Database Flashback Database can rewind an entire database back to a state of point-in-time, just before operation failures which involved whole database. The… Read More »

How to Enable Fast Recovery Area (FRA)

by Ed Chen
October 30, 2012November 1, 2022

Fast Recovery Area (FRA) Fast Recovery Area (FRA) is a very convenient feature for DBA to backup and restore database. You may set the FRA… Read More »

How to Check Free Memory in SGA Pools

by Ed Chen
October 29, 2012March 28, 2018

The dynamic view gv$sga can tell you how much memory he occupied from OS. They won't change very often. The real available memory of SGA… Read More »