Undocumented Initialization Parameters

Parameter

Description

Instance

Session

_NUMA_instance_mapping

Set of nodes that this instance should run on.

Not specified

Not specified         

_NUMA_pool_size

Aggregate size in bytes of NUMA pool.

Not specified

Not specified         

_PX_use_large_pool

Use Large Pool as source of PX buffers.

FALSE

FALSE

_abort_recovery_on_join

If TRUE, abort recovery on join reconfigurations.

FALSE

FALSE              

_active_standby_fast_reconfiguration

If TRUE, optimize dlm reconfiguration for active/standby OPS.

TRUE

TRUE               

_adaptive_direct_read*

Adaptive Direct Read.

 TRUE

TRUE               

_adaptive_fetch_enabled*

Enable/disable adaptive fetch in parallel "group by" operations.

TRUE

TRUE               

_advanced_dss_features

Enable advanced dss features; enable/disable affinity at runtime.

FALSE

FALSE              

_affinity_on

Enable/disable affinity at runtime.

TRUE

TRUE

_all_shared_dblinks

Treat all dblinks as shared.

NULL

NULL

_allocate_creation_order

Should files be examined in creation order during allocation?

FALSE

FALSE

_allocation_update_interval*

Interval at which successful search in L1 should be updated.

3

3

_allow_error_simulation

Allow error simulation for testing.

FALSE

FALSE

_allow_read_only_corruption

Allow read-only open even if database is corrupt.

FALSE

FALSE

_allow_resetlogs_corruption

Allow resetlogs even if it will cause corruption.

FALSE

FALSE

_always_anti_join*

Always use this method for anti-join when possible.

CHOOSE

CHOOSE

_always_semi_join*

Always use this method for semi-join when possible.

CHOOSE

CHOOSE

_always_star_transformation

Always favor use of star transformation.

FALSE

FALSE

_aq_tm_scanlimit

Scan limit for Time Managers to clean up IOT.

0

0

_arch_io_slaves

ARCH I/O slaves.

0

0

_async_bsp

If TRUE, BSP flushes log asynchronously (DFS).

TRUE

TRUE

_async_recovery_claims*

If TRUE, issue recovery claims a asynchronously

TRUE

TRUE

_async_recovery_reads*

If TRUE, issue recovery reads asynchronously.

TRUE

TRUE

_avoid_prepare*

If TRUE, do not prepare a buffer when the master is local.

TRUE

TRUE

_b_tree_bitmap_plans

Enable the use of bitmap plans only for tables with B-tree indexes.

TRUE

TRUE

_backup_disk_io_slaves

Backup disk I/O slaves.

0

0

_backup_io_pool_size

Memory to reserve from the large pool.

1048576

1048576

_bsp_log_flush

If TRUE, flush redo log before serving a CR buffer (DFS).

TRUE

TRUE

_bump_highwater_mark_count

How many blocks should we allocate per freelist on advancing HW?

0

0

_cgs_send_timeout*

CGS send timeout.

300

300

_check_block_after_checksum

Perform block check after checksum if both are turned on.

TRUE

TRUE

_cleanup_rollback_entries

Number of undo entries to apply per transaction cleanup.

100

100

_close_cached_open_cursors

Close cursors cached by PL/SQL at each commit.

FALSE

FALSE

_collect_undo_stats*

Collect statistics v$undostat.

TRUE

TRUE

_column_elimination_off

Turn off predicate-only column elimination.

FALSE

FALSE

_column_tracking_level*

Column usage tracking.

1

1

_compatible_no_recovery

Database will be compatible unless crash or media recovery is needed.

0.0.0

0.0.0              

_complex_view_merging

Enable complex view merging.

TRUE

TRUE

_controlfile_enqueue_timeout

Controlfile enqueue timeout in seconds.

900

900

_corrupted_rollback_segments

Corrupted undo segment list.

NULL

NULL

_cost_equality_semi_join*

Enables costing of equality semi-join.

TRUE

TRUE

_cpu_count*

Current number of CPUs for this instance.

0

0

_cpu_to_io

Divisor for converting CPU cost to I/O cost.

0

0

_cr_grant_global_role*

If TRUE, grant lock for CR requests when block is in global role.

TRUE

TRUE

_cr_grant_local_role*

If TRUE, grant lock for CR using three-way ping when block in local role.

FALSE

FALSE

_cursor_db_buffers_pinned

Additional number of buffers a cursor can pin at once. 

51

51 

_cursor_plan_enabled*

Enable collection and display of cursor plans.

TRUE

TRUE

_db_aging_cool_count

Touch count set when buffer cooled.

1

1

_db_aging_freeze_cr

Make CR buffers always be too cold to keep in cache.

FALSE

FALSE

_db_aging_hot_criteria

Touch count, which sends a buffer to head of replacement list.

2

2

_db_aging_stay_count

Touch count set when buffer moved to head of replacement list.

0

0

_db_aging_touch_time

Touch count, which sends a buffer to head of replacement list.

3

3

_db_always_check_system_ts

Always perform block check and checksum for system tablespace.

TRUE

TRUE

db_block_buffers*

Number of database blocks cached in memory: hidden  parameter.

8024

8024

_db_block_cache_clone

Always clone data blocks on get (for debugging).

FALSE

FALSE

_db_block_cache_map

Map/unmap and track reference counts on blocks (for debugging).

0

0

_db_block_cache_protect

Protect database blocks (true only when debugging).

FALSE

FALSE

_db_block_check_for_debug

Check more and dump block before image for debugging.

FALSE

FALSE

_db_block_granule_interval*

Number of LRU latches.

10

10

_db_block_hash_buckets

Number of database block hash buckets (should be prime).

16057

16057 

_db_block_hash_latches

Number of database block hash latches.

1024

1024

_db_block_hi_priority_batch_size

Fraction of writes for high-priority reasons.

0

0

_db_block_lru_latches*

Number of LRU latches.

8

8

_db_block_max_cr_dba

Maximum allowed number of CR buffers per DBA.

6

6

_db_block_max_dirty_target*

Upper bound on modified buffers/recovery reads.

0

0

_db_block_max_scan_pct*

Percentage of buffers to inspect when looking for free buffers.

40

40

_db_block_med_priority_batch_size

Fraction of writes for medium-priority reasons.

0

0

_db_block_numa

Number of NUMA nodes.

1

1

_db_block_prefetch_quota

Prefetch quota as a percent of cache size.

10

10

_db_block_trace_protect*

Trace buffer protect calls.

FALSE

FALSE

_db_file_direct_io_count*

Sequential I/O buffer size.

1048576

1048576

_db_file_noncontig_mblock_read_count

Number of noncontiguous db blocks to be prefetched.

11

11

_db_handles

Systemwide simultaneous buffer operations.

750

750

_db_handles_cached

Buffer handles cached each process.

5

5

_db_large_dirty_queue

Number of buffers that force dirty queue to be written.

25

25

_db_no_mount_lock

Do not get a mount lock.       

FALSE

FALSE

_db_percent_hot_default

Percent of default buffer pool considered hot.

50

50

_db_percent_hot_keep

Percent of keep buffer pool considered hot.

0

0

_db_percent_hot_recycle

Percent of recycle buffer pool considered hot.

0

0

_db_writer_chunk_writes

Number of writes DBWR should wait for.

0

0

_db_writer_histogram_statistics

Maintain dbwr histogram statistics in x$kcbbhs.

FALSE

FALSE

_db_writer_max_writes

Max number of outstanding DB writer I/Os.

0

0

_db_writer_scan_depth_pct*

Percentage of LRU buffers for dbwr to scan when looking for dirty buffers.

25

25

_dbwr_async_io

Enable dbwriter asynchronous writes.

TRUE

TRUE

_dbwr_scan_interval

Dbwriter scan interval.

10

10

_dbwr_tracing

Enable dbwriter tracing.

0

0

_default_non_equality_sel_check

Sanity check on default selectivity for like/range predicate.

TRUE

TRUE

_defer_multiple_waiters

If TRUE, defer down converts when there are waiters (DFS).

TRUE

TRUE

_diag_daemon*

Start DIAG daemon.

TRUE

TRUE

_disable_file_locks

Disable file locks for control, data, redo log files.

FALSE

FALSE

_disable_incremental_checkpoints

Disable incremental checkpoints for thread recovery.

FALSE

FALSE

_disable_latch_free_SCN_writes_via_32cas

Disable latch-free SCN writes using 32-bit compare and swap.

FALSE

FALSE

_disable_latch_free_SCN_writes_via_64cas

Disable latch-free SCN writes using 64-bit compare and swap.

FALSE

FALSE

_disable_logging

Disable logging.

FALSE

FALSE

_disable_multiple_block_sizes*

Disable multiple blocksize support (for debugging).

FALSE

FALSE

_disable_sun_rsm*

Disable IPC OSD support for Sun RSMAPI.

TRUE

TRUE

_discrete_transactions_enabled

Enable OLTP mode.

FALSE

FALSE

_dispatcher_rate_scale*

Scale to display rate statistic (100ths of a second).

NULL

NULL

_dispatcher_rate_ttl*

Time-to-live for rate statistic (100ths of a second).

NULL

NULL

_distributed_lock_timeout

Number of seconds a distributed transaction waits for a lock.

60

60

_distributed_recovery_connection_hold_time

Number of seconds RECO holds outbound connections open.

200

200

_dlmtrace*

Trace string of lock types(s).

NULL

NULL

_domain_index_batch_size

Maximum number of rows from one call to domain index fetch routines.

2000

2000

_domain_index_dml_batch_size

Maximum number of rows for one call to domain index DML routines.

200

200

_dss_cache_flush

Enable full cache flush for parallel execution.

FALSE

FALSE

_dump_MTTR_to_trace

Dump high-availability MTTR information to CKPT trace file.

FALSE

FALSE

_dyn_sel_est_num_blocks*

Number of blocks for dynamic selectivity estimation.

30

30

_dyn_sel_est_on*

Dynamic selectivity estimation on

FALSE

FALSE

_dynamic_stats_threshold

Delay threshold (in seconds) between sending statistics messages.

30

30

_eliminate_common_subexpr

Enables elimination of common subexpressions.

TRUE

TRUE

_enable_NUMA_optimization

Enable NUMA-specific optimizations.

TRUE

TRUE

_enable_block_level_transaction_recovery

Enable block-level recovery.

TRUE 

TRUE

_enable_cscn_caching

Enable commit SCN caching for all transactions.

TRUE

TRUE

 _enable_default_affinity

 To enable default implementation of affinity OSDS.

0

0

 _enable_kgh_policy*

Temporary to disable/enable KGH policy.

FALSE

FALSE

 _enable_list_io

Enable list I/O.

FALSE

FALSE

_enable_multitable_sampling

Enable multitable sampling.

FALSE

FALSE

_enable_type_dep_selectivity

Enable type-dependent selectivity estimates.

TRUE

TRUE

_enqueue_debug_multi_instance

Debug enqueue multi-instance.

FALSE

FALSE

_enqueue_hash

Enqueue hash table length.

375

375

_enqueue_hash_chain_latches

Enqueue hash chain latches.

1

1

 _enqueue_locks

 Locks for managed enqueues.

2230

2230

_explain_rewrite_mode*

Allow additional messages to be generated during explain.

FALSE

FALSE

_fairness_pi*

If TRUE, allow spontaneous PI buffers.

TRUE

TRUE

_fairness_threshold

Number of times to CR serve before downgrading lock (DFS).

4

4

_fast_full_scan_enabled

Enable/disable index fast full scan.

TRUE

TRUE

_fifth_spare_parameter

Fifth spare parameter: string.                               

NULL

NULL

_filesystemio_options

I/O operations on filesystem files.

asynch             

asynch    

_first_spare_parameter

 First spare parameter: integer.

NULL

NULL

_force_temptables_for_gsets*

Executes concatenation of rollups using temp tables.

FALSE

FALSE

_fourth_spare_parameter

Fourth spare parameter: string.

NULL

NULL

_full_pwise_join_enabled

Enable full partition-wise join when TRUE.

TRUE

TRUE

_gc_bsp_procs

Number of buffer server processes to start (DFS).

0

0

 _gc_defer_time

How long to defer down converts for hot buffers (DFS).

3

3

_gc_latches

 Number of latches per lock process (DFS).

2

2

 _gc_lck_procs

 Number of background parallel server lock processes to start.

0

0

_gc_releasable_locks*

Number of global cache locks (DFS).

0

0

_groupby_nopushdown_cut_ratio

Groupby nopushdown cut ratio.

3

3

_groupby_orderby_combine

Groupby/orderby don't combine threshold.

5000

5000

_gs_anti_semi_join_allowed*

Enable anti-/semi-join for the GS query.

TRUE

TRUE

_hash_multiblock_io_count*

Number of blocks hash join will read/write at once.

0

0

 _high_server_threshold

High server thresholds.

0

0

_idl_conventional_index_maintenance

Enable conventional index maintenance for insert direct.

TRUE

TRUE

_ignore_desc_in_index

Ignore DESC in indexes; sort those columns ascending anyhow.

FALSE

FALSE

_improved_outerjoin_card

Improved outer-join cardinality calculation.

TRUE

TRUE

_improved_row_length_enabled

Enable the improvements for computing the average row length.

TRUE

TRUE

_imr_active*

Activate Instance Membership Recovery feature.

TRUE

TRUE

_imr_max_reconfig_delay*              

Maximum reconfiguration delay (seconds).

300

300

_index_join_enabled

Enable the use of index joins. 

TRUE

TRUE

_index_prefetch_factor

Index prefetching factor. 

100

100

_init_sql_file

File containing SQL statements to execute upon database creation.

?/rdbms/ad min/sql.bsq

?/rdbms/ad min/sql.bsq

_insert_enable_hwm_brokered*

During parallel inserts high-water marks are brokered.

TRUE

TRUE

_inst_locking_period*

Period an instance can retain a newly acquired level 1 bitmap.

5

5      

_interconnect_checksum

If TRUE, checksum interconnect blocks (DFS).

TRUE

TRUE

_io_slaves_disabled

Do not use I/O slaves.

FALSE

FALSE

_ioslave_batch_count

Per attempt I/Os picked.

1

1

 _ioslave_issue_count

I/Os issued before completion check.

500

500

_ipc_fail_network

Simulate cluster network failure.

0

0

 _ipc_test_failover

Test transparent cluster network failover.

0

0

 _ipc_test_mult_nets

Simulate multiple cluster networks.

0

0

_job_queue_interval*

Wakeup interval in seconds for job queue coordinator.

5

5

 _kcl_debug

If TRUE, record lock escalation history (DFS).

TRUE

TRUE

_kcl_dispatch*

If TRUE, dispatch requests to bsp and lck (DFS).

FALSE

FALSE

 _kcl_name_table_latches*

Number of name table latches (DFS).

8

8

 _kcl_partition*

 If TRUE, dynamically remaster partitioned files (DFS).

FALSE

FALSE

 _kcl_use_cr*

If TRUE, use fusion CR buffers (DFS).

TRUE

TRUE

_kdbl_enable_post_allocation*

Allocate dbas after populating data buffers.

FALSE

FALSE

_keep_recovery_buffers*

If TRUE, make recovery buffers current.

TRUE

TRUE

_keep_remote_column_size*

Remote column size does not get modified.

FALSE

FALSE

_kghdsidx_count*

Max kghdsidx count.

1

1

 _kgl_bucket_count

Index to the bucket count array.

9

9

 _kgl_latch_count

Number of library cache latches.

0

0

 _kgl_multi_instance_invalidation

Whether KGL to support multi-instance invalidations.

TRUE

TRUE

_kgl_multi_instance_lock

Whether KGL to support multi-instance locks.

TRUE

TRUE

_kgl_multi_instance_pin

Whether KGL to support multi-instance pins.

TRUE

TRUE

_kkfi_trace

Trace expression substitution.

FALSE

FALSE

 _ksi_trace

KSI trace string of lock  type(s).

NULL

NULL

 _ksmg_granule_size*

Granule size in bytes.

16777216

16777216

 _ksu_diag_kill_time*

Number of seconds ksuitm waits before killing diag.

5

5

 _large_pool_min_alloc

Minimum allocation size in bytes for the large allocation pool.

16K

16K

 _last_allocation_period*

Period over which an instance can retain an active level 1 bitmap 

5

5

_latch_miss_stat_sid

SID of process for which to collect latch stats.

 0

0

_latch_recovery_alignment

Align latch recovery structures.

254

254

_ldr_io_size*

Size of write I/Os used during a load operation.

262144

262144

_left_nested_loops_random

Enable random distribution method for left of nested loops.

TRUE

TRUE

_lgwr_async_io

LGWR Asynchronous I/O enabling Boolean flag.

TRUE

TRUE

_lgwr_io_slaves

LGWR I/O slaves.

0

0

_lgwr_max_ns_wt*

Maximum wait time for LGWR to allow NetServer to progress.

30

30

_lgwr_ns_nl_max*

Variable to simulate network latency.

1000

1000

_lgwr_ns_nl_min*

Variable to simulate network latency.

500

500

_lgwr_ns_sim_err*

Variable to simulate errors during LGWR-network server testing.

0

0

_like_with_bind_as_equality

Treat LIKE predicates with bind variables as an equality predicate.

FALSE

FALSE

_lm_activate_lms_threshold*

Threshold value to activate an additional LMS.

100

100

_lm_cache_res_cleanup

Percentage of cached resources that should be cleaned up.

25

25

_lm_dd_interval

DD time interval in seconds.

60

60

_lm_direct_sends

Processes that will do direct lock manager sends.

all

all

_lm_dispatch_nonpcm*

Dispatching non-PCM messages to LMS.  

FALSE

FALSE

_lm_dispatch_pcm*

Dispatching PCM messages to LMS.

FALSE

FALSE

_lm_dynamic_lms*

Dynamic LMS invocation.

FALSE

FALSE

_lm_dynamic_remastering*

If TRUE, enables dynamic remastering.

TRUE

TRUE

_lm_lms*

Number of background lock manager server processes to start.

0

0

_lm_locks*

Number of locks configured for the lock manager.

 12000

1200

_lm_master_weight*

 Master resource weight for this instance.

1

1

_lm_max_lms*

Max. number of background lock manager server processes.

0

0

_lm_min_lms*

Min. number of background lock manager server processes.

0

0

_lm_msg_batch_size*

GES batch message size.

2048

2048

_lm_node_join_opt*

Lock manager node join optimization in reconfig.

FALSE

FALSE

_lm_non_fault_tolerant

Disable lock manager fault-tolerance mode.

FALSE

FALSE

_lm_proc_freeze_timeout*

Reconfiguration: process freeze timeout.

600

600

_lm_procs

Number of client processes configured for the lock manager.

127

127

_lm_rcfg_timeout*

Reconfiguration timeout.

180000

180000

_lm_rcv_buffer_size

The size of receive buffer.

32768

32768

_lm_res_part*

Number of resource partition configured for the lock manager.

1289

1289

_lm_ress*

Number of resources configured for the lock manager.

6000

6000

_lm_send_buffers

Number of lock manager send buffers.

10000

10000

_lm_send_queue_length*

KJCT send queue maximum length.

5000

5000

_lm_sync_timeout

Synchronization timeout for DLM reconfiguration steps.

NULL

NULL

_lm_ticket_active_sendback

Flow control ticket active sendback threshold.

NULL

NULL 

_lm_tickets*

GES messaging tickets.

1000

1000

_lm_tx_delta*

TX lock localization delta.

16

16

_lm_validate_resource_type*

If TRUE, enables resource name validation.

FALSE

FALSE

_lm_xids

Number of transaction IDs configured for the lock manager.

139

139

_local_communication_costing_enabled*

Enable local communication costing when TRUE.

TRUE

TRUE

_local_communication_ratio*

Set the ratio between global and local communication (0…100).

50

50

_lock_sga_areas

Lock-specified areas of the SGA in physical memory.

0

0

_log_archive_buffer_size

Size of each archival buffer in log file blocks.

2048

2048

_log_archive_buffers

Number of buffers to allocate for archiving.

4

4

_log_blocks_during_backup

Log block images when changed during backup.

TRUE

TRUE

_log_buffers_corrupt

Corrupt redo buffers before write.

FALSE

FALSE

_log_buffers_debug

Debug redo buffers (slows things down).

FALSE

FALSE

_log_checkpoint_recovery_check

Number of redo blocks to verify after checkpoint.

0

0

_log_debug_multi_instance

Debug redo multi-instance code FALSE.

FALSE

_log_io_size

Automatically initiate log write if this many redo blocks in buffer.

0

0

_log_simultaneous_copies

Number of simultaneous copies into redo buffer (number of copy latches)

2

2

_log_space_errors

Should we report space errors to alert log?

TRUE

TRUE

_log_switch_timeout*

Maximum number of seconds redos in the current log could span.

0

0

_low_server_threshold

Low server thresholds.

0

0

_master_direct_sends*

Direct sends for messages from master (DFS).

31

31

_mav_refresh_consistent_read*

Refresh materialized views using consistent read snapshot.

TRUE

TRUE

_mav_refresh_double_count_prevented*

Materialized view MAV refreshes avoid double counting.

FALSE

FALSE

_mav_refresh_opt*

Optimizations during refresh of materialized views.

0

0

_mav_refresh_unionall_tables*

Number of tables for unionall expansion during materialized view refresh. @@@Au: Check sense. To us it makes sense@@@

3

3

_max_exponential_sleep

Max sleep during exponential backoff.

0

0

_max_sleep_holding_latch

Max time to sleep while holding a latch.

4

4

_messages

Message queue resources: dependent on number of processes and buffers

300

300

_minimal_stats_aggregation

Prohibit stats aggregation at compile/partition maintenance time.

TRUE

TRUE

_minimum_giga_scn

Minimum SCN to start with in 2^30 units.

0

0

_multi_join_key_table_lookup*

TRUE if multijoin-key table lookup prefetch is enabled.

TRUE

TRUE

_mv_refresh_delta_fraction*

Delta MV as fractional percentage of size of MV.

10

10

_mv_refresh_eut*

Refresh materialized views using EUT (partition)-based algorithm.

TRUE

TRUE

_mv_refresh_new_setup_disabled*

Materialized view MV refresh new setup disabling.

FALSE

FALSE

_mv_refresh_selections

Create materialized views with selections and fast refresh.

TRUE

TRUE

_mv_refresh_use_stats*

Pass cardinality hints to refresh queries.

TRUE

TRUE

_nchar_imp_cnv*

NLS allow implicit conversion between CHAR and NCHAR.

TRUE

TRUE

_ncmb_readahead_enabled

Enable multiblock read-ahead for an index scan.

0

0

_ncmb_readahead_tracing

Turn on multiblock read-ahead tracing.

0

0

_nested_loop_fudge

Nested loop fudge.

100

100

_new_initial_join_orders

Enable initial join orders based on new ordering heuristics.

TRUE

TRUE

_new_sort_cost_estimate*

Enables the use of new cost estimate for sort.

TRUE

TRUE

_no_objects

No object features are used.

FALSE

FALSE

_no_or_expansion

OR expansion during optimization disabled.

FALSE

FALSE

_ns_max_flush_wt*

Flush wait time for NetServer to flush outstanding writes.

30

30

_number_cached_attributes

Maximum number of cached attributes per instance.

10

10

_offline_rollback_segments

Offline undo segment list.

NULL

NULL

_ogms_home

GMS home directory.

NULL

NULL

_old_connect_by_enabled

Enable/disable old connect-by behavior.@@@Au: By what?@@@

FALSE

FALSE

_oneside_colstat_for_equijoins

Sanity check on default selectivity for like/range predicate.

TRUE

TRUE

_open_files_limit

Limit on number of files opened by I/O subsystem.

4294967294

4294967294

_optim_enhance_nnull_detection

TRUE, to enable index [fast] full scan more often.

TRUE

TRUE

_optim_new_default_join_sel*

Improves the way default equijoin selectivity are computed.

TRUE

TRUE

_optim_peek_user_binds*

Enable peeking of user binds.

TRUE

TRUE

_optimizer_adjust_for_nulls

Adjust selectivity for null values.

TRUE

TRUE

_optimizer_choose_permutation

Force the optimizer to use the specified permutation.

0

0

_optimizer_cost_model*

Optimizer cost model.

CHOOSE

CHOOSE

_optimizer_degree

Force the optimizer to use the same degree of parallelism.

0

0

_optimizer_mode_force

Force setting of optimizer mode for user-recursive SQL also.

TRUE

TRUE

_optimizer_new_join_card_computation*

Compute join cardinality using nonrounded input values.

TRUE

TRUE

_optimizer_new_mbio*

Enables the use of new costing I/O with MBIO.

0

0

_optimizer_percent_parallel*

Optimizer percent parallel.

101

101

_optimizer_search_limit

Optimizer search limit.

5

5

_optimizer_undo_changes

Undo changes to query optimizer.

FALSE

FALSE

_or_expand_nvl_predicate

Enable OR expanded plan for NVL/DECODE predicate.

TRUE

TRUE

_oracle_trace_events

Oracle TRACE event flags.

NULL

NULL

_oracle_trace_facility_version

Oracle TRACE facility version.

NULL

NULL

_ordered_nested_loop

Enable ordered nested loop costing.

TRUE

TRUE

_ordered_semijoin

Enable ordered semi-join subquery.

TRUE

TRUE

_parallel_adaptive_max_users

Maximum number of users running with default DOP.

1

1                                     

_parallel_default_max_instances

Default maximum number of instances for parallel query.

1

1                  

_parallel_execution_message_align

Alignment of PX buffers to OS page boundary.

FALSE

FALSE

_parallel_fake_class_pct

Fake db-scheduler percent used for testing.

0

0

_parallel_load_bal_unit

Number of threads to allocate per instance.

0

0

_parallel_load_balancing

Parallel execution load-balanced slave allocation.

TRUE

TRUE

_parallel_min_message_pool

Minimum size of shared pool memory to reserve for PQ servers

64440

64440

_parallel_recovery_stopat

Stop at position to step through SMON. @@@Au: Check—what do hyphens around “position” indicate?Got me, oracle put it there@@@

32767

32767

_parallel_server_idle_time

Idle time before parallel query server dies.

5

5

_parallel_server_sleep_time

Sleep time between dequeue timeouts (in 1/100ths).

10

10

_parallel_txn_global

Enable parallel_txn hint with updates and deletes.

FALSE

FALSE

_parallelism_cost_fudge_factor

Set the parallelism cost fudge factor.

350

350

_partial_pwise_join_enabled

Enable partial partition-wise join when TRUE.

TRUE

TRUE

_passwordfile_enqueue_timeout

Password file enqueue timeout in seconds.

900

900

_pcm_fast_reconfig*

If TRUE, enable fast reconfiguration for PCM locks.

TRUE

TRUE

_pcm_latches*

Number of PCM resource hash latches to be allocated.

128

128

_pcm_resources*

Number of PCM resources to be allocated.

NULL

NULL                                

_pcm_shadow_locks*

Number of PCM shadow locks to be allocated.

NULL

NULL

_pct_refresh_double_count_prevented*

Materialized view PCT refreshes avoid double counting.

TRUE

TRUE

_pdml_gim_sampling

Control separation of global index maintenance for PDML.

5000

5000

_pdml_gim_staggered

Slaves start on different index when doing index maintenance.

FALSE

FALSE

_pdml_slaves_diff_part

Slaves start on different partition when doing index maintenance.

TRUE

TRUE

_pga_max_size*

Maximum size of the PGA memory for one process.

209715200

209715200

_ping_level*

Fusion ping level (DFS).

3

3

_plsql_dump_buffer_events

Conditions upon which the PL/SQL circular buffer is dumped.

NULL

NULL

_plsql_load_without_compile

PL/SQL load without compilation flag.

FALSE

FALSE

_pmon_load_constants*

Server load-balancing constants (S, P, D, I, L, C, M).

300,192,64 300,192,64,3,10,10,0

300,192,64,3,10,10,0         

_pre_rewrite_push_pred*

Push predicates into views before rewrite.

FALSE

FALSE

_pred_move_around*

Enables predicate move-around. 

TRUE

TRUE

_predicate_elimination_Enabled

Allow predicate elimination if set to true. @@@Au: If set to what?@@@

TRUE

TRUE

_project_view_columns

Enable projecting out unreferenced columns of a view

TRUE

TRUE

_push_join_predicate

Enable pushing join predicate inside a view

TRUE

TRUE

_push_join_union_view

Enable pushing join predicate inside a UNION view.

TRUE

TRUE

_px_async_getgranule

Asynchronous get granule in the slave.

FALSE

FALSE

_px_broadcast_fudge_factor

Set the TQ broadcasting fudge factor percentage.

100

100

_px_granule_size

Default size of a rowid range granule (in KB).

100000

100000             

_px_index_sampling

Parallel query sampling for index create (100000 = 100%).

200

200

_px_kxib_tracing

Turn on kxib tracing.

0

0

_px_load_publish_interval

Interval at which LMON will check whether to publish PX load.

200

200

_px_max_granules_per_slave

Maximum number of rowid range granules to generate per slave.

100

100

_px_min_granules_per_slave

Minimum number of rowid range granules to generate per slave.

13

13

_px_no_stealing

Prevent parallel granule stealing in shared nothing environment.

FALSE

FALSE

_px_trace*

PX trace parameter.

none

none

_query_cost_rewrite

Perform the cost-based rewrite with materialized views.

TRUE

TRUE

_query_rewrite_1*

Perform query rewrite before and after or only before view merging.

TRUE

TRUE

_query_rewrite_2

Perform query rewrite before and after or only after view merging.

TRUE

TRUE

_query_rewrite_drj*

MV rewrite, and drop redundant joins.

TRUE

TRUE

_query_rewrite_expression

Rewrite with canonical form for expressions.

TRUE

TRUE

_query_rewrite_fpc*

MV rewrite fresh partition containment.

TRUE

TRUE

_query_rewrite_fudge

Cost-based query rewrite with MV fudge factor.

90

90

_query_rewrite_jgmigrate*

MV rewrite with jg migration.

TRUE

TRUE

_query_rewrite_or_error*

Allow query rewrite, if referenced tables are not dataless.

FALSE

FALSE

_query_rewrite_vop_cleanup

Prune frocol chain before rewrite after view merging.

TRUE

TRUE

_realfree_heap_free_threshold*

Threshold for performing real-free, in Kbytes.

64

64

_realfree_heap_max_size*

Minimum max total heap size, in Kbytes.

32768

32768

_recovery_claim_batch_size*

Number of messages to batch in a recovery claim message (DFS).

10

10                 

_recovery_percentage*

Recovery buffer cache percentage

80

80                 

_release_insert_threshold

Maximum number of unusable blocks to unlink from freelist.

5

5                  

_reliable_block_sends*

If TRUE, block sends across interconnect are reliable.

FALSE

FALSE

_reuse_index_loop

Number of blocks being examined for index block reuse.

5

5

_rollback_segment_count

Number of undo segments.

0

0

_rollback_segment_initial

Starting undo segment number.  

1

1

_row_cache_buffer_size

Size of row cache circular buffer.

200

200

_row_cache_cursors

Number of cached cursors for row cache management.

10

10

_row_cache_instance_locks

Number of row cache instance locks.

100

100 

_scn_scheme

SCN scheme.

NULL

NULL

_second_spare_parameter*

Second spare parameter: integer.

NULL

NULL

_send_close_with_block*

If TRUE, send close with block, even with direct sends.

TRUE

TRUE

_serial_direct_read

Enable direct read in serial

FALSE

FALSE

_session_idle_bit_latches

One latch per session or a latch per group of sessions.

0

0

_seventh_spare_parameter*

Seventh spare parameter: string list.

NULL

NULL

_shared_pool_reserved_min_alloc

Minimum allocation size in bytes for reserved area of shared pool.

4400

4400

_shared_pool_reserved_pct*

Percentage memory of the shared pool allocated for the reserved section.

5

5

_shrunk_aggs_disable_threshold*

Percentage of exceptions at which to switch to full-length aggregates.

60

60

_shrunk_aggs_enabled*

Enable use of variable-sized buffers for nondistinct aggregates.

TRUE

TRUE

_side_channel_batch_size*

Number of messages to batch in a side channel message (DFS).

100

100

_single_process

Run without detached processes.

FALSE

FALSE

 _sixth_spare_parameter*

Sixth spare parameter: string list.

NULL

NULL

 _skip_assume_msg*

If TRUE, skip assume message for consigns at the master.

TRUE

TRUE

 _slave_mapping_enabled*

Enable slave mapping when TRUE.

TRUE

TRUE

 _slave_mapping_group_size*

Force the number of slave group in a slave mapper.

0

0

 _small_table_threshold

Threshold level of table size for direct reads.

160

160

 _smm_auto_cost_enabled*

If TRUE, use the AUTO size policy cost functions.

FALSE

FALSE

 _smm_auto_max_io_size*

Maximum I/O size (in KB) used by sort/hash-join in auto mode.

248

248

 _smm_auto_min_io_size*

Minimum I/O size (in KB) used by sort/hash-join in auto mode.

56

56

 _smm_bound*

Overwrites memory manager automatically computed bound.

0

0

 _smm_control*

Provides controls on the memory manager.

0

0

 _smm_max_size*

Maximum work area size in auto mode (serial).

0

0

 _smm_min_size*

Minimum work area size in auto mode.

128

128

 _smm_px_max_size*

Maximum work area size in auto mode (global).

0

0

 _smm_trace*

Turn on/off tracing for SQL memory manager.

0

0

 _smon_internal_errlimit*

Limit of SMON internal errors.

100

100

 _smu_debug_mode*

<debug-flag> Set debug event for testing SMU operations.

0

0

 _smu_error_simulation_site*

Site ID of error simulation in KTU code.

0

0

 _smu_error_simulation_type*

Error type for error simulation in KTU code.

0

0

 _sort_elimination_cost_ratio

Cost ratio for sort elimination under first_rows mode.

0

0

 _sort_multiblock_read_count*

Multiblock read count for sort.

2

2

 _sort_space_for_write_buffers

Tenths of sort_area_size devoted to direct write buffers.

1

1

_sortmerge_inequality_join_off

Turns off sort-merge join on inequality.

FALSE

FALSE

_spin_count

Amount to spin waiting for a latch.

1

1

_sql_connect_capability_override

SQL Connect Capability Table override.

0

0

 _sql_connect_capability_table

SQL Connect Capability Table (testing only).

NULL

NULL

 _sqlexec_progression_cost

SQL execution progression monitoring cost threshold.

1000

1000

_subquery_pruning_cost_factor

Subquery pruning cost factor.

20

20

 _subquery_pruning_enabled

Enable the use of subquery predicates to perform pruning.

TRUE

TRUE

_subquery_pruning_mv_enabled*

Enable the use of subquery predicates with MVs to perform  pruning.

TRUE

TRUE

 _subquery_pruning_reduction

Subquery pruning reduction factor.

50

50

 _system_index_caching*

Optimizer percent system index caching.

0

0

 _system_trig_enabled

Are system triggers enabled?   

TRUE

TRUE

 _table_lookup_prefetch_size*

Table lookup prefetch vector size.

40

40

 _table_scan_cost_plus_one

Bump estimated full table scan cost by one.

FALSE

FALSE

 _temp_tran_block_threshold

Number of blocks for a dimension before we temp transform.

100

100

 _temp_tran_cache

Determines if temp table is created with cache option.

TRUE

TRUE

 _test_param_1

Test parmeter 1: integer.

25

25

 _test_param_2

Test parameter 2:  string.

NULL

NULL

 _test_param_3

Test parameter 3:  string.

NULL

NULL

 _test_param_4*

Test parameter 4: string list.

NULL

NULL

 _test_param_5*

Test parmeter 5: deprecated integer.

25

25

 _test_param_6*

Test parmeter 6:  size (ub8).

0

0

 _third_spare_parameter

Third spare parameter:  integer.

NULL

NULL

 _tq_dump_period

Time period for duping of TQ statistics (s).

0

0

 _trace_archive*

Start DIAG process.

FALSE

FALSE

 _trace_buffer_flushes

Trace buffer flushes if otrace cacheIO event is set.

FALSE

FALSE

 _trace_buffer_gets

 Trace kcb buffer gets if otrace cacheIO event is set.

FALSE

FALSE

 _trace_buffers*

Trace buffer sizes per process

ALL:256

ALL:256            

_trace_cr_buffer_creates

Trace cr buffer creates if otrace cacheIO event is set.

FALSE

FALSE

 _trace_events

Trace events enabled at startup.

NULL

NULL

 _trace_file_size

Maximum size of trace file (in number of trace records).

65536

65536

 _trace_files_public

Create publicly accessible trace files.

FALSE

FALSE

 _trace_flush_processes*

Trace data archived by DIAG for these processes.

ALL

ALL

 _trace_instance_termination

Trace instance termination actions.

FALSE

FALSE

 _trace_multi_block_reads

Trace multi_block reads if otrace cacheIO event is set.

FALSE

FALSE

 _trace_options*

 Trace data flush options.

text,multiple

text,multiple

 _trace_processes*

Enable KST tracing in process.

ALL

ALL

 _transaction_recovery_servers

Max number of parallel recovery slaves that may be used.

0

0

 _tts_allow_nchar_mismatch

Allow plugging in a tablespace with a different national character set.

 FALSE

 FALSE

 _two_pass*

Enable two-pass thread recovery.

TRUE

TRUE

 _unnest_notexists_sq*

Unnest NOT EXISTS subquery with one or more tables if possible.

SINGLE

SINGLE

 _unnest_subquery

Enables unnesting of correlated subqueries.

TRUE

TRUE

 _use_column_stats_for_function

Enable the use of column statistics for DDP functions.

TRUE

TRUE

 _use_ism

Enable shared page tables – ISM.

TRUE

TRUE

 _use_new_explain_plan*

If TRUE, use the AUTO size policy cost functions.

FALSE

FALSE

 _use_nosegment_indexes

Use nosegment indexes in explain plan.

FALSE

FALSE

 _use_realfree_heap*

Use real free-based allocator for PGA memory.

FALSE

FALSE

 _use_vector_post

Use vector post.

TRUE

TRUE

 _verify_undo_quota*

If TRUE; verify consistency of undo quota statistics.

FALSE

FALSE

 _wait_for_sync

Wait for sync on commit MUST ALWAYS BE TRUE.

TRUE

TRUE

 _walk_insert_threshold

Maximum number of unusable blocks to walk across freelist.

0

0

 _write_clones

Write clones flag.

3

3

_yield_check_interval

Interval to check whether actses should yield.

100000

100000