My Precious Databank

Check the standby server: SQL> SELECT database_role FROM v$database; Stop the MRP process and switch to primary mode: SQL> RECOVER MANAGED STANDBY DATABASE CANCEL; SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH; SQL> ALTER DATABASE ACTIVATE STANDBY DATABASE; SQL> ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=DEFER SCOPE=BOTH SID='*'; Restart the standby database and verify it is in primary mode: SQL> SHUTDOWN IMMEDIATE; SQL> STARTUP; SQL> SELECT database_role FROM v$database; For setups with two or more standby servers: Check the data flow between standby servers. If an issue occurs with redirect_dml mode, restart the standby servers to resolve the problem. Note: Ensure the failover process is monitored carefully to avoid data inconsistencies.

Database Switchover Steps 1. Pre-operation Steps Check archive logs on both the primary and standby servers: Primary: SELECT thread#, MAX(sequence#) "Last Primary Seq Generated" FROM gv$archived_log val, gv$database vdb WHERE val.resetlogs_change# = vdb.resetlogs_change# GROUP BY thread# ORDER BY 1; Standby: SELECT thread#, MAX(sequence#) "Last Standby Seq Received" FROM gv$archived_log val, gv$database vdb WHERE val.resetlogs_change# = vdb.resetlogs_change# GROUP BY thread# ORDER BY 1; Verify the last applied log sequence: SELECT thread#, MAX(sequence#) "Last Standby Seq Applied" FROM gv$archived_log val, gv$database vdb WHERE val.resetlogs_change# = vdb.resetlogs_change# AND val.applied IN ('YES', 'IN-MEMORY') GROUP BY thread# ORDER BY 1; Verify initialization parameters: Ensure the following parameters are correctly configured: SELECT name, value FROM v$parameter WHERE UPPER(name) IN ('DB

The following steps can be used to quickly reconfigure a corrupted standby database in Oracle Data Guard. These steps assume the configurations are already in place, and the commands below should be executed on the standby server. 1. Create a PFILE Create a PFILE from the current SPFILE: create pfile='/tmp/pfile.ora' from spfile; 2. Drop the Old Standby Database Use RMAN to drop the old standby database: RMAN> startup mount; RMAN> sql 'alter system enable restricted session'; RMAN> drop database including backups noprompt; 3. Create SPFILE from the PFILE After dropping the database, recreate the SPFILE from the previously created PFILE: sqlplus / as sysdba create spfile from pfile='/tmp/pfile.ora'; startup nomount; 4. Start Database Recovery Use RMAN to duplicate the database for standby: rman target sys@DWHPRI auxiliary sys@DWHDG duplicate target database for standby from active database dorecover nofilenamecheck; 5. Manage S

1. Identify Large Segments in the SYSTEM Tablespace Before deleting records, you may want to identify which segments occupy the most space in the SYSTEM tablespace. Run the following SQL command: SET PAGES 999 SET LINES 300 COL OWNER FOR A10 COL SEGMENT_NAME FOR A20 COL SEGMENT_TYPE FOR A15 COL MB FOR 9999999 SELECT OWNER, SEGMENT_NAME, SEGMENT_TYPE, ROUND(BYTES/1024/1024) MB FROM DBA_SEGMENTS WHERE TABLESPACE_NAME='SYSTEM' ORDER BY BYTES DESC FETCH FIRST 5 ROWS ONLY; 2. Count Audit Records Older Than 180 Days To estimate the number of audit records that are older than 180 days, use this query: SELECT COUNT(*) FROM SYS.AUD$ WHERE ntimestamp# < SYSDATE - 180; 3. Delete Audit Records in Batches To prevent undo tablespace issues during deletion, remove records in smaller batches. Use the following PL/SQL block: DECLARE v_limit NUMBER := 10000; -- Define batch size BEGIN LOOP DELETE FROM SYS.AUD$

1. Check the Current Configuration Before making any changes, verify if memory_target is set: SHOW PARAMETER memory_target; If memory_target is not 0, follow these steps: 2. Check Current SGA and PGA Values Run the following commands to view the current configurations: SHOW PARAMETER sga_target; SHOW PARAMETER sga_max_size; SHOW PARAMETER pga_aggregate_target; 3. Calculate and Set New Targets To adjust the SGA and PGA sizes, use the following commands. Replace the values with your desired configuration if needed: ALTER SYSTEM SET SGA_TARGET = 32G SCOPE = SPFILE; ALTER SYSTEM SET SGA_MAX_SIZE = 32G SCOPE = SPFILE; ALTER SYSTEM SET PGA_AGGREGATE_TARGET = 24G SCOPE = SPFILE; Note: If Automatic Memory Management (AMM) is enabled ( memory_target is not 0), adjust only MEMORY_TARGET instead of SGA_TARGET and PGA_AGGREGATE_TARGET . 4. Restart the Database To apply the changes, restart the database: SHUTDOWN IMMEDIATE; STARTUP; 5. Verify the New Configurati