Sunday, December 21, 2014

ORA-38500 While Enabling Real-Time Redo Apply

Issuing “ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE” returns error message “ORA-38500: USING CURRENT LOGFILE option not available without stand”

The reason for this error message is related to log applies service. “USING CURRENT LOGFILE” option means we want to have “real time apply”, and “real time apply” needs standby redo log files to be created in the standby database before we can use this feature.

To avoid this error, we need to add standby redo log groups in standby database because real time apply needs LGWR to write redo log data from primary; directly to the standby redo log groups at standby site. Oracle recommends to create “total number of primary redo log file group + 1” standby redo log groups in standby database. Formula to calculate the standby redo log groups is as follows

(maximum number of logfiles +1) * maximum number of threads

Size of standby redo log groups should be same as primary redo log groups. Following command can be used to add standby redo log groups in standby database.
ALTER DATABASE ADD STANDBY LOGFILE GROUP <group #> <’logfile path’>
SIZE <size in megabytes>M;


No comments: