December 24, 2019

init parameters in Oracle RAC

Special init parameters in Oracle RAC
(which are not available in stand-alone Oracle Database instance)


instance_number
Oracle Real Application Clusters (RAC) parameter specifies a unique number that maps the instance.

instance_group
This RAC parameter specifies one or more instance groups and assigns the current instance to those groups.

thread
This RAC init parameter specifies the number of the redo thread to be used by an instance.

cluster_database
Oracle Real Application Clusters (RAC) parameter that specifies whether or not Real Application Clusters is enabled.

cluster_database_instances
Oracle Real Application Clusters (RAC) parameter that specifies the number of instances that are configured as part of the cluster database.

cluster_interconnects
This RAC parameter provides Oracle with information about additional cluster interconnects available for use in Real Application Clusters environments.

remote_listener
local_listener
parallel_instance
max_commit_propagation_delay

init parameters, in Oracle RAC, with SAME VALUE across all instances
active_instance_count
archive_lag_target
compatible
cluster_database
cluster_database_instances
cluster_interconnects       
control_files
db_block_size
db_domain
db_files
db_name
db_recovery_file_dest
db_recovery_file_dest_size
db_unique_name
dml_locks                     -- when 0
instance_type                -- rdbms or asm
max_commit_propagation_delay
parallel_max_servers
remote_login_password_file
trace_enabled
undo_management

For example,
*.cluster_database=true
*.cluster_database_instances=2
*.compatible='11.2.0.2'
*.undo_management='AUTO'

init parameters, in Oracle RAC, with Unique Values across all instances
instance_number
instance_name
thread
undo_tablespace/rollback_segments

For example,
INST1.instance_number=1
INST1.instance_name=rac1
INST1.thread=1
INST1.undo_tablespace='UNDOTBS1'

INST2.instance_number=2
INST2.instance_name=rac2
INST2.thread=2
INST2.undo_tablespace='UNDOTBS2'

Other Oracle RAC Articles:     crsctl commands RAC    srvctl commands RAC     cluvfy commands RAC


2 comments:

  1. Nice post. Thanks for sharing such a useful information. Oracle RAC training

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  2. Hi Satya, and everyone.

    Recently I'd set a hidden parameter for testing on a standalone server due to a bug (parameter _cgs_health_check_in_reconfig, Doc ID 1949505.1 of Oracle Support). The parameter is dynamic and applied successfully with "scope=both"; the change was registered at the alert log. But suddenly, on the next restart, it was reversed to its original value.

    I've been searching for the reason with no success yet but I'm guessing it's because this is a RAC parameter applied on a standalone database.

    Does anyone knows something about this?

    Thanks and regards,
    Boris


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