Dataguard Syntax Short

This little list has proven to be quite usefull for me. Escpesially since they made the commands so loooong. Its all there in the manual, but with a lot more stuff around it ;).

Be Aware! The lines break like the wave Maveric in this blog!

Physical standby database commands

Goal
Mount a standby database
Command
SQL> alter database mount standby database;

Goal
Start Redo Apply (Normal Recovery Process)
Command
SQL> alter database recover managed standby database disconnect;

Goal
Start Real Time Apply
Command
SQL> alter database recover managed standby database using current logfile disconnect;

Goal
Stop Apply (Redo or Real Time)
Command
SQL> alter database recover managed standby database cancel;

Goal
Run the recovery process in paralell (Number of CPU*2)
Command
alter database recover managed standby database using current logfile disconnect paralell 16;

Logical standby database commands

Goal
Start SQL Apply
Command
SQL> alter database start logical standby apply;

Goal
Start SQL Apply with Real Time Apply
Command
SQL> alter database start logical standby apply immediate;

Goal
Stop SQL Apply
Command
SQL> alter database stop logical standby apply;

Switchover

Goal
Check if you database is ready to switch over
Command
SQL> select switchover_status from v$database;
Expected result
SWITCHOVER_STATUS
-----------------
TO PRIMARY



Other commands

Goal
List information about archivelogs (I just had to put it in here, cause its cute)
Command
SQL> archive log list;

Going to ASM...

Converting non-ASM databases to ASM is quite easy...if you know what to do ;).

Actually I had to convert a non-ASM standby database to a two instance RAC ASM-database as part of a catastropical test. Why doing it this way, is really a good question. I will just say I'm trying to convince my customer to use Dataguard as the product is intended. No luck yet ;).

Here we go...

The tool you really need to know is RMAN! You don't get anywhere without RMAN working with ASM. This is not entirely true, but that's another story.

So basically you have a backup set of your non-ASM database. The files are typically stored on "/u02/oradata/SID/..." and so on... You ned RMAN to restore these files to ASM instead of "/u02/oradata/SID/...". To do this I use something called "set newname". The syntax is:

set newname for datafile 1 to '+DATA'

The reference "+DATA" is your diskgroup in ASM.

So, at some point you need to know how many datafiles you have, and probably how many tempfiles you have. You will typically have to write a little script like this:

connect / as sysdba
whenever sqlerror exit sql.sqlcode
set space 0
set pages 0
set heading off
set echo off
set trimspool on
set verify off
set feedback off
spool rman_newname_restore.rcv
select 'configure DEVICE TYPE DISK parallelism 4;' from dual;
select 'run' from dual;
select '{' from dual;
select 'set newname for datafile ' file# ' to ''' name '.dbf'';' from
v$datafile;
select 'restore database;' from dual;
select '}' from dual;
spool off;

Then you use the rman_newname_restore.rcv for the restore script. Rman will then restore your files to the new location set by newname.

There might be better solutions than mine, so I'm looking forward to reading your replays.