二、隱藏引數

Oracle 系統中還有一類引數稱之為隱藏引數 (hidden parameters) ，是系統中使用，但 Oracle 官方沒有公佈的引數，這些引數可能是那些還沒有成熟或者是系統開發中使用的引數。這些引數在所有 Oracle 官方提供的文件中都沒有介紹，他們的命名有一個共同特徵就是都以 '_' 作為引數的首字元，諸如 Oracle 8i 中的 _trace_files_public 和 _lock_sga_areas 等等。特別宣告：用到隱含引數時要謹慎。

下面的查詢可以得到當前系統中的所有隱藏引數 ( 以 sys 身份登入 ) ：

SQL> col ksppinm for a30
SQL> col ksppstvl for a5
SQL> col ksppdesc for a25
SQL> select ksppinm,ksppstvl,ksppdesc
2 from x$ksppi x,x$ksppcv y
3 where x.indx=y.indx
4 and translate(ksppinm,'_','#') like '#%';

_ior_serialize_fault           0     inject fault in the ior s
                                     erialize code

_inject_startup_fault          0     inject fault in the start
                                     up code

_latch_recovery_alignment      65534 align latch recovery stru
                                     ctures

_spin_count                    2000 Amount to spin waiting fo
                                     r a latch

_latch_miss_stat_sid           0     Sid of process for which
                                     to collect latch stats

_max_sleep_holding_latch       4     max time to sleep while h
                                     olding a latch

_max_exponential_sleep         0     max sleep during exponent
                                     ial backoff

_other_wait_threshold          0     threshold wait percentage
                                      for event wait class Oth
                                     er

_other_wait_event_exclusion          exclude event names from
                                     _other_wait_threshold cal
                                     culations

_use_vector_post               TRUE use vector post
_latch_class_0                       latch class 0
_latch_class_1                       latch class 1
_latch_class_2                       latch class 2
_latch_class_3                       latch class 3
_latch_class_4                       latch class 4
_latch_class_5                       latch class 5
_latch_class_6                       latch class 6
_latch_class_7                       latch class 7
_latch_classes                       latch classes override
_ultrafast_latch_statistics    TRUE maintain fast-path statis
                                     tics for ultrafast latche
                                     s

_enable_reliable_latch_waits   TRUE Enable reliable latch wai
                                     ts

_wait_breakup_time_csecs       300   Wait breakup time (in cen
                                     tiseconds)

_wait_breakup_threshold_csecs 600   Wait breakup threshold (i
                                     n centiseconds)

_disable_wait_stack            FALSE Disable wait stack
_session_idle_bit_latches      0     one latch per session or
                                     a latch per group of sess
                                     ions

_ksu_diag_kill_time            5     number of seconds ksuitm
                                     waits before killing diag

_ksuitm_dont_kill_dumper       FALSE delay inst. termination t
                                     o allow processes to dump

_disable_image_check           FALSE Disable Oracle executable
                                      image checking

_num_longop_child_latches      2     number of child latches f
                                     or long op array

_longops_enabled               TRUE longops stats enabled
_test_ksusigskip               5     test the function ksusigs
                                     kip

_disable_kcbhxor_osd           FALSE disable kcbh(c)xor OSD fu
                                     nctionality

_disable_system_state          42949 disable system state dump
                               67294

_session_wait_history          10    enable session wait histo
                                     ry collection

_session_idle_check_interval   60    Resource Manager session
                                     idle limit check interval
                                      in seconds

_pkt_enable                    FALSE enable progressive kill t
                                     est

_pkt_start                     FALSE start progressive kill te
                                     st instrumention

_pkt_pmon_interval             50    PMON process clean-up int
                                     erval (cs)

_dead_process_scan_interval    60    PMON dead process scan in
                                     terval

_collapse_wait_history         FALSE collapse wait history
_short_stack_timeout_ms        30000 short stack timeout in ms
_sga_early_trace               0     sga early trace event
_kill_session_dump             TRUE Process dump on kill sess
                                     ion immediate

_logout_storm_rate             0     number of processes that
                                     can logout in a second

_logout_storm_timeout          5     timeout in centi-seconds
                                     for time to wait between
                                     retries

_logout_storm_retrycnt         600   maximum retry count for l
                                     ogouts

_ksuitm_addon_trccmd                 command to execute when d
                                     ead processes don't go aw
                                     ay

_timeout_actions_enabled       TRUE enables or disables KSU t
                                     imeout actions

_idle_session_kill_enabled     TRUE enables or disables resou
                                     rce manager session idle
                                     limit checks

_disable_vktm                  FALSE disable vktm process
_disable_highres_ticks         FALSE disable high-res tick counter

鑑於隱含引數有1627行，這裡只列出一部分，在留言板中將列出全部。這裡絕大多數對我們來說是用不到的。再次宣告:對於隱含引數我們要慎用。

三、系統當前引數

下面的指令碼以英文字母順序列出了系統當前使用的所有引數。在列出的引數中，如果引數名稱前面有 # 這個符號，則表示該引數沒有明確指定，採用了系統中的預設引數。一般在一個新的 Oracle 版本安裝完成後，首先執行該指令碼，則可以生成該版本資料庫的標準 init.ora 檔案。

SQL>SELECT DECODE(isdefault, 'TRUE', '# ') || DECODE(isdefault, 'TRUE', RPAD(name,43), RPAD(name,45)) || ' = ' || value

2 FROM v$parameter

3 ORDER BY name;

注意：上面的 SQL 指令碼沒有列出系統中的隱藏引數。

# O7_DICTIONARY_ACCESSIBILITY                 = FALSE
# active_instance_count                       =
# aq_tm_processes                             = 0
# archive_lag_target                          = 0
# asm_diskgroups                              =
# asm_diskstring                              =
# asm_power_limit                             = 1
# asm_preferred_read_failure_groups           =
audit_file_dest                               = F:\APP\YANG\ADMIN\ORACL\ADUMP
# audit_sys_operations                        = FALSE
audit_trail                                   = DB
# background_core_dump                        = partial
# background_dump_dest                        = f:\app\yang\diag\rdbms\oracl\ora
cl\trace

# backup_tape_io_slaves                       = FALSE
# bitmap_merge_area_size                      = 1048576
# blank_trimming                              = FALSE
# buffer_pool_keep                            =
# buffer_pool_recycle                         =
# circuits                                    =
# client_result_cache_lag                     = 3000
# client_result_cache_size                    = 0
# cluster_database                            = FALSE
# cluster_database_instances                  = 1
# cluster_interconnects                       =
# commit_logging                              =
# commit_point_strength                       = 1
# commit_wait                                 =
# commit_write                                =
compatible                                    = 11.1.0.0.0
# control_file_record_keep_time               = 7
control_files                                 = F:\APP\YANG\ORADATA\ORACL\CONTRO
L01.CTL, F:\APP\YANG\ORADATA\ORACL\CONTROL02.CTL, F:\APP\YANG\ORADATA\ORACL\CONT
ROL03.CTL

# control_management_pack_access              = DIAGNOSTIC+TUNING
# core_dump_dest                              = f:\app\yang\diag\rdbms\oracl\ora
cl\cdump

# cpu_count                                   = 2
# create_bitmap_area_size                     = 8388608
# create_stored_outlines                      =
# cursor_sharing                              = EXACT
# cursor_space_for_time                       = FALSE
# db_16k_cache_size                           = 0
# db_2k_cache_size                            = 0
# db_32k_cache_size                           = 0
# db_4k_cache_size                            = 0
# db_8k_cache_size                            = 0
# db_block_buffers                            = 0
# db_block_checking                           = FALSE
# db_block_checksum                           = TYPICAL
db_block_size                                 = 8192
# db_cache_advice                             = ON
# db_cache_size                               = 0
# db_create_file_dest                         =
# db_create_online_log_dest_1                 =
# db_create_online_log_dest_2                 =
# db_create_online_log_dest_3                 =
# db_create_online_log_dest_4                 =
# db_create_online_log_dest_5                 =
db_domain                                     =
# db_file_multiblock_read_count               = 128
# db_file_name_convert                        =
# db_files                                    = 200
# db_flashback_retention_target               = 1440
# db_keep_cache_size                          = 0
# db_lost_write_protect                       = NONE
db_name                                       = oracl
db_recovery_file_dest                         = F:\app\yang\flash_recovery_area
db_recovery_file_dest_size                    = 2147483648
# db_recycle_cache_size                       = 0
# db_securefile                               = PERMITTED
# db_ultra_safe                               = OFF
# db_unique_name                              = oracl
# db_writer_processes                         = 1
# dbwr_io_slaves                              = 0
# ddl_lock_timeout                            = 0
# dg_broker_config_file1                      = F:\APP\YANG\PRODUCT\11.1.0\DB_1\
DATABASE\DR1ORACL.DAT

# dg_broker_config_file2                      = F:\APP\YANG\PRODUCT\11.1.0\DB_1\
DATABASE\DR2ORACL.DAT

# dg_broker_start                             = FALSE
diagnostic_dest                               = F:\APP\YANG
# disk_asynch_io                              = TRUE
dispatchers                                   = (PROTOCOL=TCP) (SERVICE=oraclXDB
)

# distributed_lock_timeout                    = 60
# dml_locks                                   = 748
# drs_start                                   = FALSE
# enable_ddl_logging                          = FALSE
# event                                       =
# fal_client                                  =
# fal_server                                  =
# fast_start_io_target                        = 0
# fast_start_mttr_target                      = 0
# fast_start_parallel_rollback                = LOW
# file_mapping                                = FALSE
# fileio_network_adapters                     =
# filesystemio_options                        =
# fixed_date                                  =
# gc_files_to_locks                           =
# gcs_server_processes                        = 0
# global_context_pool_size                    =
# global_names                                = FALSE
# global_txn_processes                        = 1
# hash_area_size                              = 131072
# hi_shared_memory_address                    = 0
# hs_autoregister                             = TRUE
# ifile                                       =
# instance_groups                             =
# instance_name                               = oracl
# instance_number                             = 0
# instance_type                               = RDBMS
# java_jit_enabled                            = TRUE
# java_max_sessionspace_size                  = 0
# java_pool_size                              = 0
# java_soft_sessionspace_limit                = 0
# job_queue_processes                         = 1000
# large_pool_size                             = 0
# ldap_directory_access                       = NONE
# ldap_directory_sysauth                      = no
# license_max_sessions                        = 0
# license_max_users                           = 0
# license_sessions_warning                    = 0
# local_listener                              =
# lock_name_space                             =
# lock_sga                                    = FALSE
# log_archive_config                          =
# log_archive_dest                            =
log_archive_dest_1                            = location=f:\app\yang\archive1
# log_archive_dest_10                         =
log_archive_dest_2                            = location=f:\app\yang\archive2
# log_archive_dest_3                          =
# log_archive_dest_4                          =
# log_archive_dest_5                          =
# log_archive_dest_6                          =
# log_archive_dest_7                          =
# log_archive_dest_8                          =
# log_archive_dest_9                          =
log_archive_dest_state_1                      = ENABLE
# log_archive_dest_state_10                   = enable
# log_archive_dest_state_2                    = enable
# log_archive_dest_state_3                    = enable
# log_archive_dest_state_4                    = enable
# log_archive_dest_state_5                    = enable
# log_archive_dest_state_6                    = enable
# log_archive_dest_state_7                    = enable
# log_archive_dest_state_8                    = enable
# log_archive_dest_state_9                    = enable
# log_archive_duplex_dest                     =
log_archive_format                            = %s_%t_%r.log
# log_archive_local_first                     = TRUE
log_archive_max_processes                     = 5
log_archive_min_succeed_dest                  = 2
log_archive_start                             = TRUE
# log_archive_trace                           = 0
# log_buffer                                  = 5653504
# log_checkpoint_interval                     = 0
# log_checkpoint_timeout                      = 1800
# log_checkpoints_to_alert                    = FALSE
# log_file_name_convert                       =
# max_commit_propagation_delay                = 0
# max_dispatchers                             =
# max_dump_file_size                          = unlimited
# max_enabled_roles                           = 150
# max_shared_servers                          =
# memory_max_target                           = 859832320
memory_target                                 = 859832320
# nls_calendar                                =
# nls_comp                                    = BINARY
# nls_currency                                =
# nls_date_format                             =
# nls_date_language                           =
# nls_dual_currency                           =
# nls_iso_currency                            =
# nls_language                                = AMERICAN
# nls_length_semantics                        = BYTE
# nls_nchar_conv_excp                         = FALSE
# nls_numeric_characters                      =
# nls_sort                                    =
# nls_territory                               = AMERICA
# nls_time_format                             =
# nls_time_tz_format                          =
# nls_timestamp_format                        =
# nls_timestamp_tz_format                     =
# object_cache_max_size_percent               = 10
# object_cache_optimal_size                   = 102400
# olap_page_pool_size                         = 0
open_cursors                                  = 300
# open_links                                  = 4
# open_links_per_instance                     = 4
# optimizer_capture_sql_plan_baselines        = FALSE
# optimizer_dynamic_sampling                  = 2
# optimizer_features_enable                   = 11.1.0.6
# optimizer_index_caching                     = 0
# optimizer_index_cost_adj                    = 100
# optimizer_mode                              = ALL_ROWS
# optimizer_secure_view_merging               = TRUE
# optimizer_use_invisible_indexes             = FALSE
# optimizer_use_pending_statistics            = FALSE
# optimizer_use_sql_plan_baselines            = TRUE
# os_authent_prefix                           = OPS$
# os_roles                                    = FALSE
# parallel_adaptive_multi_user                = TRUE
# parallel_automatic_tuning                   = FALSE
# parallel_execution_message_size             = 2148
# parallel_instance_group                     =
# parallel_io_cap_enabled                     = FALSE
# parallel_max_servers                        = 20
# parallel_min_percent                        = 0
# parallel_min_servers                        = 0
# parallel_server                             = FALSE
# parallel_server_instances                   = 1
# parallel_threads_per_cpu                    = 2
# pga_aggregate_target                        = 0
# plscope_settings                            = IDENTIFIERS:NONE
# plsql_ccflags                               =
# plsql_code_type                             = INTERPRETED
# plsql_debug                                 = FALSE
# plsql_native_library_dir                    =
# plsql_native_library_subdir_count           = 0
# plsql_optimize_level                        = 2
# plsql_v2_compatibility                      = FALSE
# plsql_warnings                              = DISABLE:ALL
# pre_page_sga                                = FALSE
processes                                     = 150
# query_rewrite_enabled                       = TRUE
# query_rewrite_integrity                     = enforced
# rdbms_server_dn                             =
# read_only_open_delayed                      = FALSE
# recovery_parallelism                        = 0
# recyclebin                                  = on
# redo_transport_user                         =
# remote_dependencies_mode                    = TIMESTAMP
# remote_listener                             =
remote_login_passwordfile                     = EXCLUSIVE
# remote_os_authent                           = FALSE
# remote_os_roles                             = FALSE
# replication_dependency_tracking             = TRUE
# resource_limit                              = FALSE
# resource_manager_cpu_allocation             = 2
# resource_manager_plan                       = SCHEDULER[0x2C0E]:DEFAULT_MAINTE
NANCE_PLAN

# result_cache_max_result                     = 5
# result_cache_max_size                       = 1245184
# result_cache_mode                           = MANUAL
# result_cache_remote_expiration              = 0
# resumable_timeout                           = 0
# rollback_segments                           =
# sec_case_sensitive_logon                    = TRUE
# sec_max_failed_login_attempts               = 10
# sec_protocol_error_further_action           = CONTINUE
# sec_protocol_error_trace_action             = TRACE
# sec_return_server_release_banner            = FALSE
# serial_reuse                                = disable
# service_names                               = oracl
# session_cached_cursors                      = 50
# session_max_open_files                      = 10
# sessions                                    = 170
# sga_max_size                                = 536870912
# sga_target                                  = 0
# shadow_core_dump                            = none
# shared_memory_address                       = 0
# shared_pool_reserved_size                   = 6081740
shared_pool_size                              = 121634816
# shared_server_sessions                      =
# shared_servers                              = 1
# skip_unusable_indexes                       = TRUE
# smtp_out_server                             =
# sort_area_retained_size                     = 0
# sort_area_size                              = 65536
# spfile                                      = F:\APP\YANG\PRODUCT\11.1.0\DB_1\
DATABASE\SPFILEORACL.ORA

# sql92_security                              = FALSE
# sql_trace                                   = FALSE
# sql_version                                 = NATIVE
# sqltune_category                            = DEFAULT
# standby_archive_dest                        = %ORACLE_HOME%\RDBMS
# standby_file_management                     = MANUAL
# star_transformation_enabled                 = FALSE
# statistics_level                            = TYPICAL
# streams_pool_size                           = 0
# tape_asynch_io                              = TRUE
# thread                                      = 0
# timed_os_statistics                         = 0
# timed_statistics                            = TRUE
# trace_enabled                               = TRUE
# tracefile_identifier                        =
# transactions                                = 187
# transactions_per_rollback_segment           = 5
# undo_management                             = AUTO
undo_retention                                = 900
undo_tablespace                               = UNDOTBS1
# use_indirect_data_buffers                   = FALSE
# user_dump_dest                              = f:\app\yang\diag\rdbms\oracl\ora
cl\trace

# utl_file_dir                                =
# workarea_size_policy                        = AUTO
# xml_db_events                               = enable

已選擇288行。

Oracle資料庫系統中的引數（續）

相關文章