Tag Archives: policy managed database

An introduction to Policy Managed Databases in 11.2 RAC

I just realised this week that I haven’t really detailed anything about policy managed RAC databases. I remembered having done some research about server pools way back when 11.2.0.1 came out. I promised to spend some time looking at the new type of database that comes with server pools: policy managed databases but somehow didn’t get around to doing it. Since I’m lazy I’ll refer to these databases as PMDs from now on as it saves a fair bit of typing.

So how are PMDs different from Administrator Managed Databases?

First of all you can have PMDs with RAC only, i.e. in a multi-instance active/active configuration. Before 11.2 RAC you had to tie an Oracle instance to a cluster node. This is why you see instance prefixes in a RAC spfile. Here is an example from my lab 11.2.0.3.6 cluster:

DEMO1.__db_cache_size=1073741824
[...]
DEMO2.__streams_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/DEMO/adump'
*.audit_trail='db'
*.cluster_database=true
*.compatible='11.2.0.0.0'
*.control_files='...'
*.db_block_size=8192
*.db_create_file_dest='+DATA'
*.db_domain=''
*.db_name='DEMO'
*.db_recovery_file_dest='+RECO'
*.db_recovery_file_dest_size=4558159872
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=DEMOXDB)'
DEMO2.instance_number=2
DEMO1.instance_number=1
*.nls_language='ENGLISH'
*.nls_territory='UNITED KINGDOM'
*.open_cursors=300
*.pga_aggregate_target=310378496
*.processes=300
*.remote_listener='rac11gr2scan.example.com:1521'
*.remote_login_passwordfile='exclusive'
*.sessions=335
*.sga_target=1610612736
DEMO1.thread=1
DEMO2.thread=2
DEMO1.undo_tablespace='UNDOTBS2'
DEMO2.undo_tablespace='UNDOTBS1'

Note that the instance_number, thread and undo tablespace are manually (=administrator) managed. If these aren’t set or configured incorrectly you will run into all sorts of fun. Continue reading