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Don Burleson Blog 









Oracle 8i hidden disable & enable parameters

Don Burleson


Note: Oracle hidden parameters are undocumented and unsupported by Oracle.
Make sure that you thoroughly test all hidden parameters before placing them in your production environment.

Parameter Name                            Description
----------------------------------------- ----------------------------------------------------------------
_disable_file_locks                       disable file locks for control, data, redo log files
_disable_incremental_checkpoints          Disable incremental checkpoints for thread recovery
_disable_kcbhxor_osd                      disable kcbh(c)xor OSD functionality
_disable_latch_free_SCN_writes_via_32cas  disable latch-free SCN writes using 32-bit compare & swap
_disable_latch_free_SCN_writes_via_64cas  disable latch-free SCN writes using 64-bit compare & swap
_disable_logging                          Disable logging
_disable_multiple_block_sizes             disable multiple block size support (for debugging)
_disable_odm                              disable odm feature
_disable_recoverable_recovery             Disable the new recoverable recovery mechanism
_disable_savepoint_reset                  disable the fix for bug 1402161
_disable_sun_rsm                          Disable IPC OSD support for Sun RSMAPI
_disable_system_state                     disable system state dump 
_enable_block_level_transaction_recovery  enable block level recovery
_enable_cscn_caching                      enable commit SCN caching for all transactions
_enable_default_affinity                  to enable default implementation of affinity osds
_enable_kgh_policy                        temporary to disable/enable kgh policy
_enable_list_io                           Enable List I/O
_enable_multitable_sampling               enable multitable sampling
_enable_NUMA_optimization                 Enable NUMA specific optimizations
_enable_type_dep_selectivity              enable type dependent selectivity estimates



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