12cR2 lots of new instance parameters


Comparing database 12cR1 release to 12cR2 release, I see these new parameters:

adg_imc_enabled                               TRUE                 Enable IMC support on ADG                                                                                                  
allow_global_dblinks                          FALSE                LDAP lookup for DBLINKS                                                                                                    
allow_group_access_to_sga                     FALSE                Allow read access for SGA to users of Oracle owner group                                                                   
approx_for_aggregation                        FALSE                Replace exact aggregation with approximate aggregation                                                                     
approx_for_count_distinct                     FALSE                Replace count distinct with approx_count_distinct                                                                          
approx_for_percentile                         none                 Replace percentile_* with approx_percentile                                                                                
asm_io_processes                              0                    number of I/O processes per domain in the ASM IOSERVER instance                                                            
cdb_cluster                                   FALSE                if TRUE startup in CDB Cluster mode                                                                                        
cdb_cluster_name                              cfcdba1              CDB Cluster name                                                                                                           
clonedb_dir                                                        CloneDB Directory                                                                                                          
containers_parallel_degree                    65535                Parallel degree for a CONTAINERS() query                                                                                   
cursor_invalidation                           IMMEDIATE            default for DDL cursor invalidation semantics                                                                              
data_guard_sync_latency                       0                    Data Guard SYNC latency                                                                                                    
data_transfer_cache_size                      0                    Size of data transfer cache                                                                                                
default_sharing                               metadata             Default sharing clause                                                                                                     
disable_pdb_feature                           0                    Disable features                                                                                                           
enable_dnfs_dispatcher                        FALSE                Enable DNFS Dispatcher                                                                                                     
enable_pdb_isolation                          FALSE                Enables Pluggable Database isolation inside a CDB                                                                          
enabled_PDBs_on_standby                       *                    List of Enabled PDB patterns                                                                                               
encrypt_new_tablespaces                       ALWAYS               whether to encrypt newly created tablespaces                                                                               
external_keystore_credential_location         +DATA/wallets/tde/us external keystore credential location                                                                                      
inmemory_expressions_capture                  DISABLE              Controls detection of frequently used costly expressions                                                                   
inmemory_expressions_usage                    ENABLE               Controls which In-Memory Expressions are populated in-memory                                                               
inmemory_virtual_columns                      ENABLE               Controls which user-defined virtual columns are stored in-memory                                                           
instance_abort_delay_time                     0                    time to delay an internal initiated abort (in seconds)                                                                     
instance_mode                                 READ-WRITE           indicates whether the instance read-only or read-write or read-mostly                                                      
long_module_action                            TRUE                 Use longer module and action                                                                                               
max_idle_time                                 60                   maximum session idle time in minutes                                                                                       
max_iops                                      0                    MAX IO per second                                                                                                          
max_mbps                                      0                    MAX MB per second                                                                                                          
ofs_threads                                   4                    Number of OFS threads                                                                                                      
one_step_plugin_for_pdb_with_tde              FALSE                Facilitate one-step plugin for PDB with TDE encrypted data                                                                 
optimizer_adaptive_plans                      TRUE                 controls all types of adaptive plans                                                                                       
optimizer_adaptive_statistics                 FALSE                controls all types of adaptive statistics                                                                                  
outbound_dblink_protocols                     ALL                  Outbound DBLINK Protocols allowed                                                                                          
pga_aggregate_xmem_limit                      0                    limit of aggregate PGA XMEM memory consumed by the instance                                                                
remote_recovery_file_dest                                          default remote database recovery file location for refresh/relocate                                                        
sec_protocol_allow_deprecated_rpcs            YES                  Allow deprecated TTC RPCs                                                                                                  
standby_db_preserve_states                    NONE                 Preserve state cross standby role transition                                                                               
target_pdbs                                   525                  Parameter is a hint to adjust certain attributes of the CDB                                                                
uniform_log_timestamp_format                  TRUE                 use uniform timestamp formats vs pre-12.2 formats 

A lot of them are to do with Multitenant. The others? Well, some are fairly obvious, some used to be _underscore parameters. As for the others, I'll have to wait until I can study the docs.

John Watson
Oracle Certified Master DBA