|
Documented
|
|
Query for documented initialization parameters |
set pagesize 35
set linesize 150
col NAME format a30
col VALUE format a20
col DESCRIPTION format a60
set pause on
set pause 'Hit enter to continue'
SELECT x.ksppinm NAME,
y.ksppstvl VALUE,
ksppdesc DESCRIPTION
FROM x$ksppi x, x$ksppcv y
WHERE x.inst_id = userenv('Instance')
AND y.inst_id = userenv('Instance')
AND x.indx = y.indx
AND SUBSTR(x.ksppinm,1,1) ^= '_'
ORDER BY 1;
|
| |
|
ANSI Compliance
|
| BLANK_TRIMMING
Default: FALSE |
Specifies the data assignment semantics of character datatypes.
Allows the data assignment of a source character string or variable to a destination character column or variable even though the source length is longer than the destination length. In this case, however, the additional length over the destination length is all blanks. |
| Range of values TRUE | FALSE |
| |
|
ASM
|
ASM_DISKGROUPS
Default: NULL |
Specifies a list of names of disk groups to be mounted by an Automatic Storage Management instance at instance startup or when an ALTER DISKGROUP ALL MOUNT statement is issued. |
| Range of values Comma-separated list of strings, of up to 30 characters
in length |
ASM_DISKSTRING
Default: NULL |
An operating system-dependent value used by Automatic Storage Management to limit the set of disks considered for discovery |
| Value is comma delimited string
of disks |
ASM_POWER_LIMIT
Default: 1 |
Specifies the maximum power on an Automatic Storage Management instance for disk rebalancing. |
| Syntax ASM_POWER_LIMIT = {1 to 11} |
| |
|
Auditing
|
AUDIT_FILE_DEST
Default: No Entry |
The operating system directory into which the audit trail is written when the AUDIT_TRAIL initialization parameter is set to
os. |
| Default value ORACLE_HOME/rdbms/audit |
AUDIT_SYS_OPERATIONS
Default: FALSE |
Enables or disables the auditing of operations issued by user SYS, and users connecting with SYSDBA or SYSOPER privileges. |
| Syntax AUDIT_SYS_OERATIONS =
{TRUE |
FALSE} |
AUDIT_TRAIL
Default: NONE |
Enables or disables database auditing. |
| Syntax AUDIT_TRAIL = {DB |
OS | NONE | TRUE | FALSE | DB_EXTENDED} |
| |
|
Backup and Restore
|
BACKUP_TAPE_IO_SLAVES
Default: FALSE |
Specifies if I/O server processes (also called slaves) are used by Recovery Manager to back up, copy, or restore data to tape. |
| Range of values TRUE | FALSE |
| RECYCLEBIN |
Specifies if the recyclebin is used to
hold dropped tables and associated indexes |
| Range of values ON | OFF |
| TAPE_ASYNCH_IO |
x |
| TBD |
| |
|
BFILEs
|
| SESSION_MAX_OPEN_FILES |
x |
| TBD |
| |
|
Buffer Cache and I/O
|
DB_nK_CACHE_SIZE
Defaults: 0 |
Specifies the size of the cache for the nK buffers. You can set this parameter only when DB_BLOCK_SIZE has a value other than
nK. |
| Range of values Minimum: 0 (values greater than zero are rounded up to the nearest granule size) |
DB_BLOCK_BUFFERS
Default: 0 |
Specifies the number of database buffers in the buffer cache. It is one of several parameters that contribute to the total memory requirements of the SGA of an instance. |
| Range of values 50 to an operating system-specific maximum.
DB_BLOCK_BUFFERS cannot be combined with the dynamic DB_CACHE_SIZE parameter. |
| DB_BLOCK_SIZE |
Specifies (in bytes) the size of Oracle database blocks. For Real Application Clusters, this parameter affects the maximum value of the FREELISTS storage parameter for tables and indexes. Oracle uses one database block for each freelist group. Decision support system (DSS) and data warehouse database environments tend to benefit from larger block size values. |
| Range of values 2048 to 32768, but your operating system may have a narrower range |
DB_CACHE_ADVICE
Default: ON |
Enables or disables statistics gathering used for predicting behavior with different cache sizes through the V$DB_CACHE_ADVICE performance view. |
| Syntax DB_CACHE_ADVICE = {ON | READY | OFF} |
DB_CACHE_SIZE
Default 0 ... which conflicts with the doc. |
Specifies the size of the DEFAULT buffer pool for buffers with the primary block size (the block size defined by the DB_BLOCK_SIZE initialization parameter). |
| Syntax DB_CACHE_SIZE = integer [K | M | G]. A value of zero is illegal. |
DB_FILE_MULTIBLOCK_READ_COUNT
Default: 8 |
One of the parameters you can use to minimize I/O during table scans. It specifies the maximum number of blocks read in one I/O operation during a sequential
scan (applies to full table scans and index fast full scans, so non-random I/O.). The total number of I/Os needed to perform a full table scan depends on such factors as the size of the table, the multiblock read count, and whether parallel execution is being utilized for the operation.
Online transaction processing (OLTP) and batch environments typically have values in the range of 4 to 16 for this parameter. DSS and data warehouse environments tend to benefit most from maximizing the value of this parameter. The optimizer is more likely to choose a full table scan over an index if the value of this parameter is high.
The maximum value is always less than the operating system's maximum I/O size expressed as Oracle blocks ((max I/O size)/DB_BLOCK_SIZE). If you set this parameter to a value greater than the maximum, Oracle uses the maximum.
Depending on your exact version and the use of system statistics with version 9+ larger values for the
db_file_multiblock_read_count
parameter influence the cost based optimizer to favor full table scans
over using indexes. |
| Range of values Operating system-dependent. |
| DB_KEEP_CACHE_SIZE |
Specifies the size of the KEEP buffer pool. The size of the buffers in the KEEP buffer pool is the primary block size (the block size defined by the DB_BLOCK_SIZE initialization parameter). |
Minimum: 0 (values greater than zero are rounded up to the nearest granule size)
Maximum: operating system-dependent |
| DB_RECYCLE_CACHE_SIZE |
Specifies the size of the RECYCLE buffer pool. The size of the buffers in the RECYCLE pool is the primary block size (the block size defined by the DB_BLOCK_SIZE initialization parameter). |
Minimum: 0 (values greater than zero are rounded up to the nearest granule size)
Maximum: operating system-dependent |
| DB_WRITER_PROCESSES |
Specifies the initial number of database writer processes for an instance. |
| Range of values 1 to 20 |
| DBWR_IO_SLAVES |
Relevant only on systems with only one database writer process (DBW0). It specifies the number of I/O server processes used by the DBW0 process. The DBW0 process and its server processes always write to disk. By default, the value is 0 and I/O server processes are not used.
If you set DBWR_IO_SLAVES to a nonzero value, the number of I/O server processes used by the ARCH and LGWR processes is set to 4. However, the number of I/O server processes used by Recovery Manager is set to 4 only if asynchronous I/O is disabled (either your platform does not support asynchronous I/O or disk_asynch_io is set to false).
Typically, I/O server processes are used to simulate asynchronous I/O on platforms that do not support asynchronous I/O or that implement it inefficiently. However, you can use I/O server processes even when asynchronous I/O is being used. In that case the I/O server processes will use asynchronous I/O.
I/O server processes are also useful in database environments with very large I/O throughput, even if asynchronous I/O is enabled. |
| Range of values 0 to operating system-dependent |
DISK_ASYNCH_IO
Default: TRUE |
Controls whether I/O to datafiles, control files, and logfiles is asynchronous (that is, whether parallel server processes can overlap I/O requests with CPU processing during table scans.
Oracle recommends that you leave this parameter set to its default value. However, if the asynchronous I/O implementation is not stable, you can set this parameter to false to disable asynchronous I/O. If your platform does not support asynchronous I/O to disk, this parameter has no effect.
If you set DISK_ASYNCH_IO to false, then you should also set DBWR_IO_SLAVES to a value other than its default of zero in order to simulate asynchronous I/O. |
| Range of values TRUE | FALSE |
| FILESYSTEMIO_OPTIONS |
|
| |
| READ_ONLY_OPEN_DELAYED |
|
| |
| USE_INDIRECT_DATA_BUFFERS |
|
| |
| |
|
Cursors and Library Cache
|
CURSOR_SHARING
Default: Exact |
FORCE: Forces statements that may differ in some literals, but are otherwise identical, to share a cursor, unless the literals affect the meaning of the statement.
SIMILAR: Causes statements that may differ in some literals, but are otherwise identical, to share a cursor, unless the literals affect either the meaning of the statement or the degree to which the plan is optimized.
EXACT: Only allows statements with identical text to share the same cursor. |
| Syntax CURSOR_SHARING = {SIMILAR | EXACT | FORCE} |
CURSOR_SPACE_FOR_TIME
Default: FALSE |
Shared SQL areas are kept pinned in the shared pool. As a result, shared SQL areas are not aged out of the pool as long as an open cursor references them. Because each active cursor's SQL area is present in memory, execution is faster. However, the shared SQL areas never leave memory while they are in use. Therefore, you should set this parameter to
TRUE only when the shared pool is large enough to hold all open cursors simultaneously.
In addition, a setting of TRUE retains the private SQL area allocated for each cursor between executions instead of discarding it after cursor execution, saving cursor allocation and initialization time.
FALSE: Shared SQL areas can be deallocated from the library cache to make room for new SQL statements. |
| Syntax CURSOR_SPACE_FOR_TIME =
{TRUE |
FALSE} |
| OPEN_CURSORS |
x |
| TBD |
| SESSION_CACHED_CURSORS |
x |
| TBD |
| |
|
Database / Instance /
Identification
|
DB_DOMAIN
Default: NULL |
In a distributed database system, DB_DOMAIN specifies the logical location of the database within the network structure. |
| Range of values Any legal string of name components, separated by periods and up to 128 characters long (including the periods). This value cannot be NULL. |
| DB_NAME |
Specifies a database identifier of up to 8 characters. This parameter must be specified and must correspond to the name specified in the CREATE DATABASE statement. |
| Syntax DB_NAME = database_name |
| INSTANCE_NAME |
|
| |
| |
|
Diagnostics / Statistics (separate
these)
|
BACKGROUND_CORE_DUMP
Default: partial |
Specifies whether Oracle includes the SGA in the core file for Oracle background processes. |
| Syntax BACKGROUND_CORE_DUMP = {PARTIAL
| FULL} |
| BACKGROUND_DUMP_DEST |
Deprecated / Ignored in 11g |
CORE_DUMP_DEST
Default: {ORACLE_HOME}/dbs |
Primarily a UNIX parameter not supported on all
platforms. It specifies the directory where Oracle dumps core files. |
| {ORACLE_HOME}/dbs |
DB_BLOCK_CHECKING
Default FALSE |
Controls whether Oracle performs block checking for data blocks. When this parameter is set to
TRUE, Oracle performs block checking for all data blocks. When it is set to false, Oracle does not perform block checking for blocks in the user tablespaces. However, block checking for the SYSTEM tablespace is always turned on. |
| Range of values TRUE | FALSE |
DB_BLOCK_CHECKSUM
Default: TRUE |
Determines whether DBWn and the direct loader will calculate a checksum (a number calculated from all the bytes stored in the block) and store it in the cache header of every data block when writing it to disk. Checksums are verified when a block is read-only if this parameter is
TRUE and the last write of the block stored a checksum. In addition, Oracle gives every log block a checksum before writing it to the current log. |
| Range of values TRUE | FALSE |
| DIAGNOSTIC_DEST |
Replacement for BDUMP and UDUMP related
parameters. Points to ADR_BASE |
col name_col_plus_show_param
format a30
col type format a10
col value_col_plus_show_param format a30
show parameter diag |
| EVENT |
Debug event control - default null string [CHAR] |
| Do not alter the value of this parameter except under the supervision of Oracle Support Services staff |
| MAX_DUMP_FILE_SIZE |
Specifies the maximum size of trace files (excluding the alert file).
Valid values are: 0 to unlimited |
| TBD |
| SHADOW_CORE_DUMP |
Specifies whether Oracle includes the SGA in the core file for foreground (client) processes.
Valid values are: PARTIAL, FULL, NONE |
| TBD |
| STATISTICS LEVEL |
Specifies the level of collection for database and operating system statistics. The Oracle Database collects these statistics for a variety of purposes, including making self-management decisions.
Valid values are: ALL, TYPICAL, BASIC |
| TBD |
| TIMED_OS_STATISTICS |
When TRUE statistics are collected and stored in trace files or displayed in the V$SESSTATS and V$SYSSTATS dynamic performance
views |
| TBD |
| TRACE_ENABLED |
Controls tracing of the execution history, or code path, of Oracle. Oracle Support Services uses this information for debugging. |
| TBD |
| TRACEFILE_IDENTIFIER |
Specifies a custom identifier that becomes part of the Oracle Trace file name.
A custom identifier is used to identify a trace file simply from its name and without having to open it or view its contents. |
| TBD |
| USER_DUMP_DEST |
Deprecated / Ignored in 11g |
| |
|
Distributed Replication
|
COMMIT_POINT_STRENGTH
Default: 1 |
relevant only in distributed database systems.
Specifies a value that determines the commit point site in a distributed transaction. The node in the transaction with the highest value for COMMIT_POINT_STRENGTH will be the commit point site. |
| Range of values 0 to 255 |
DISTRIBUTED_LOCK_TIMEOUT
Default: 60 |
Specifies the amount of time (in seconds) for distributed transactions to wait for locked resources. |
| Range of values 1 to unlimited |
| GLOBAL_NAMES |
|
| TBD |
| HS_AUTOREGISTER |
|
| TBD |
| OPEN_LINKS |
|
| TBD |
| OPEN_LINKS_PER_INSTANCE |
|
| TBD |
REPLICATION_DEPENDENCY
_TRACKING |
|
| TBD |
| |
|
File Locations, Names, and Sizes
|
| CONTROL_FILES |
Control file names list [file_path,file_path..] |
| TBD |
DB_CREATE_FILE_DEST
Default: NULL |
Specifies the default location for Oracle-managed
datafiles. |
| Syntax DB_CREATE_FILE_DEST = directory | disk group |
DB_CREATE_ONLINE_LOG_DEST_n
Default: NULL |
Specifies the default location for Oracle-managed control files and online redo logs. |
| Syntax DB_CREATE_ONLINE_LOG_DEST_[1 | 2 | 3 | 4 | 5] = directory | disk group |
DB_FILES
Default: 200 |
Minimum: the largest among the absolute file numbers of the datafiles in the database
Maximum: operating system-dependent |
| Specifies the maximum number of database files that can be opened for this database. |
| DB_RECOVERY_FILE_DEST |
Specifies the default location for the flash recovery area. |
| Syntax DB_RECOVERY_FILE_DEST =
{DIRECTORY | DISK GROUP} |
| DB_RECOVERY_FILE_DEST_SIZE |
Specifies (in bytes) the hard limit on the total space to be used by target database recovery files created in the flash recovery area. |
| Syntax DB_RECOVERY_FILE_DEST_SIZE = integer [K | M | G] |
| FILE_MAPPING |
|
| TBD |
| IFILE |
|
| TBD |
| LOG_ARCHIVE_DEST_n |
|
| TBD |
| SPFILE |
|
| TBD |
| |
| |
| |
O7_DICTIONARY_ACCESSIBILITY
Default: FALSE
|
Version 7 Dictionary Accessibility support
|
| Range of values TRUE or FALSE |
ACTIVE_INSTANCE_COUNT
Default: NULL
|
Designate one instance in a two-instance cluster as the primary instance and the other instance as the secondary
instance. This parameter has no functionality in a cluster with more than two instances. |
|
Range of values 1 or >= the number of instances in the cluster. (Values other than 1 have no effect on the
active or standby status of any instances.) |
AQ_TM_PROCESSES
Default: 0 |
Required for Advanced Queuing |
| Range of values 0 to 10 |
ARCHIVE_LAG_TARGET
Default: 0 |
Limits the amount of data that can be lost and effectively increases the availability of the standby database by forcing a log switch after the specified amount of time elapses.
The ARCHIVE_LAG_TARGET initialization parameter causes Oracle to examine an instance's current online redo log periodically. If the following conditions are met the instance will switch the log:
* The current log was created prior to n seconds ago, and the estimated archival time for the current log is m seconds (proportional to the number of redo blocks used in the current log), where n + m exceeds the value of the ARCHIVE_LAG_TARGET initialization parameter.
* The current log contains redo records.
In an Oracle Real Application Clusters environment, the instance also kicks other threads into switching and archiving logs if they are falling behind. This can be particularly useful when one instance in the cluster is
less active than the other instances.
The parameter specifies the target of how many seconds of redo the standby could lose in the event of a primary shutdown or crash. It also provides an upper limit of how long (in the number of seconds) the current log of the primary database can span. Because the estimated archival time is also considered, this is not the exact log switch time. |
| Value 0 or any integer in [60, 7200] |
| BITMAP_MERGE_AREA_SIZE
Default: 1048576 for W2K & Linux |
For systems containing bitmap indexes: Specifies the amount of memory Oracle uses to merge bitmaps retrieved from a range scan of the index.
The default value is 1 MB. A larger value usually improves performance, because the bitmap segments must be sorted before being merged into a single bitmap. |
| Range of values Operating system-dependent |
| BUFFER_POOL_KEEP
Default: NULL |
Number of database blocks/latches in keep buffer pool [CHAR:
(buffers:n, latches:m)] |
| |
| BUFFER_POOL_RECYCLE
Default: NULL |
Number of database blocks/latches in recycle buffer pool [CHAR:
(buffers:n, latches:m)] |
| |
CIRCUITS
Default: NULL |
Specifies the total number of virtual circuits that are available for inbound and outbound network sessions. It is one of several parameters that contribute to the total SGA requirements of an instance. |
| Integer: There is no default
value |
CLUSTER_DATABASE
Default: FALSE |
Specifies whether or not Real Application Clusters is enabled. |
| Range of values TRUE | FALSE |
CLUSTER_DATABASE_INSTANCES
Default: 1 |
Specifies the number of instances that are configured as part of
a RAC database. |
| Range of values Any nonzero value |
CLUSTER_INTERCONNECTS
Default: NULL |
Range of values One or more IP addresses, separated by colons |
| Providesinformation about additional cluster interconnects available for use in
a RAC environments. |
| COMMIT_WRITE |
Sets transaction commit log write behavior |
| |
| COMPATIBLE |
Allows you to use a new release of Oracle, while at the same time guaranteeing backward compatibility with an earlier release.
This is not TRUE with 10g so be sure to read the documentation
carefully. |
| Range of values for 10g: 9.2.0 to default release
value |
CONTROL_FILE_RECORD_KEEP_TIME
Default: 7 |
specifies the minimum number of days before a reusable record in the control file can be reused. In the event a new record needs to be added to a reusable section and the oldest record has not aged enough, the record section expands. If this parameter is set to 0, then reusable sections never expand, and records are reused as needed. |
| Range of values 0 to 365 (days) |
| CPU_COUNT |
Specifies the number of CPUs available to Oracle. On single-CPU computers, the value of CPU_COUNT is 1. |
| Range of values 0 to unlimited |
CREATE_BITMAP_AREA_SIZE
Default: 8388608 |
Relevant only for systems containing bitmap indexes. It specifies the amount of memory (in bytes) allocated for bitmap creation. The default value is 8 MB. A larger value may speed up index creation. |
| Range of values Operating system-dependent. |
CREATE_STORED_OUTLINES
Default: NULL |
Enables automatic outline creation for subsequent queries in the same session. These outlines receive a unique system-generated name and are stored in the DEFAULT category. If a particular query already has an outline defined for it in the DEFAULT category, then that outline will remain and a new outline will not be created. |
| Syntax CREATE_STORED_OUTLINES = {TRUE
| FALSE | CATEGORY_NAME} |
DB_FILE_NAME_CONVERT
Defalt: NULL |
Useful for creating a duplicate database for recovery purposes. You can also use
DB_FILE_NAME_CONVERT to rename the datafiles in the clone controlfile when setting up a clone database during tablespace point-in-time recovery. |
| Syntax DB_FILE_NAME_CONVERT = 'string1' , 'string2' , 'string3' , 'string4' , ... |
DB_FLASHBACK_RETENTION_TARGET
Default: 1440 |
Specifies the upper limit (in minutes) on how far back in time the database may be flashed back. |
| Range of values 0 to 232 - 1 (max value represented by 32 bits) |
DB_SECUREFILE
Default: PERMITTED |
x
Requires the tablespace is created with SEGMENT SPACE MANAGEMENT =
AUTO |
| x |
| DB_UNIQUE_NAME |
Specifies a globally unique name for the database. Databases with the same DB_NAME within the same DB_DOMAIN.
Every database's DB_UNIQUE_NAME must be unique within the enterprise. |
| Syntax DB_UNIQUE_NAME = database_unique_name |
DDL_WAIT_FOR_LOCKS
Default: FALSE |
Specifies whether DDL statements (such as ALTER TABLE ... ADD COLUMN) wait and complete instead of timing out if the statement is not able to acquire all required locks. |
| Range of values TRUE | FALSE |
| DG_BROKER_CONFIG_FILEn |
Specifies the names for the Data Guard broker configuration files. Every database that is part of a Data Guard broker configuration has two broker configuration files, which contain entries that describe the state and properties of the configuration (such as the sites and databases that are part of the configuration, the roles and properties of each of the databases, and the state of each of the elements of the configuration). Two files are provided so as to always maintain the last known good state of the configuration.
If DG_BROKER_CONFIG_FILEn is not explicitly defined, then it is set to an operating system-specific default value at instance startup. The parameter can only be altered when the DMON (Data Guard broker) process is not running. |
| Range of values One filename |
DG_BROKER_START
Default: FALSE |
Enables Oracle to determine whether or not the DMON (Data Guard broker) process should be started. |
| Range of values TRUE | FALSE |
| DISPATCHERS |
|
| |
DML_LOCKS
|
Default value Derived: 4 * TRANSACTIONS. Specifies the maximum number of DML locks—one for each table modified in a transaction. The value should equal the grand total of locks on tables currently referenced by all users. For example, if three users are modifying data in one table, then three entries would be required. If three users are modifying data in two tables, then six entries would be required. |
| Range of values 20 to unlimited; a setting of 0 disables enqueues |
DRS_START
Default: FALSE |
Start DG Broker monitor (DMON process) [TRUE |
FALSE] |
| Range of values TRUE | FALSE |
ENQUEUE_RESOURCES |
Resources for enqueues [NUMBER] |
Not modifiable. Derived from the SESSIONS parameter |
| FAL_CLIENT |
Specifies the FAL (fetch archive log) client name that is used by the FAL service |
| FAL_CLIENT = string |
| FAL_SERVER |
Specifies the FAL (fetch archive log) server for a standby database |
| FAL_SERVER = string |
| FAST_START_IO_TARGET |
Deprecated in favor of FAST_START_MTTR_TARGET |
| See FAST_START_MTTR_TARGET |
| FAST_START_MTTR_TARGET |
Specify the number of seconds the database takes to perform crash recovery of a single instance.
Is overridden by FAST_START_IO_TARGET and LOG_CHECKPOINT_INTERVAL |
| Range of values 0 to 3600 seconds |
| FAST_START_PARALLEL_ROLLBACK |
Determines the maximum number of processes that can exist for performing parallel rollback. This parameter is useful on systems in which some or all of the transactions are long running |
| Range of values {HI | LO | FALSE} |
| fileio_network_adapters |
|
| |
| fixed_date |
|
| |
| gc_files_to_locks |
|
| |
| gcs_server_processes |
|
| |
| global_context_pool_size |
|
| |
| hash_area_size |
|
| |
| hi_shared_memory_address |
|
| |
| instance_groups |
|
| |
| instance_number |
|
| |
| instance_type |
|
| |
| java_max_sessionspace_size |
|
| |
| java_pool_size |
|
| |
| java_soft_sessionspace_limit |
|
| |
| job_queue_processes |
|
| |
| large_pool_size |
|
| |
| ldap_directory_access |
|
| |
| license_max_sessions |
|
| |
| |
|
| |
| OPTIMIZER_INDEX_CACHING |
A point that is often overlooked with optimizer_index_caching
is that it supposed to apply only for index costs during nested loops (although it does seem to be applied for inlist
iterators).
Consequently it is not really a measure of what fraction of an index is cached, it is a measure of how many rows I
select from a driving table that require me to collect the same data from the inner table repeatedly.
For example:
If I select 5 rows from table A and then
join to table B, it is possible that I will do a physical read for the index blocks for tableB after reading the first row from table A - but then use the same index blocks for the join to
the next 4 rows from table A.
In this case, an optimizer_index_caching value of 80% would be the representative value.
by: Jonathan Lewis / 4 Nov 2004
A relevant metalink note (62286.1) would suggest that Oracle intend the
value to be considered for in-list as well as NL.
by: Niall Litchfield |
| |
|
|
|
Undocumented
|
| Query for undocumented initialization parameters |
set pagesize 35
set linesize 150
col NAME format a40
col VALUE format a20
col DESCRIPTION format a60
set pause on
set pause 'Hit enter to continue'
SELECT x.ksppinm NAME,
y.ksppstvl VALUE,
ksppdesc DESCRIPTION
FROM x$ksppi x, x$ksppcv y
WHERE x.inst_id = userenv('Instance')
AND y.inst_id = userenv('Instance')
AND x.indx = y.indx
AND SUBSTR(x.ksppinm,1,1) = '_'
ORDER BY 1;
|
_NEWSORT_ENABLED
Default: TRUE |
Activates new sorting algorithm in 10gR2 |
Range of values TRUE | FALSE
alter session set "_newsort_enabled"=FALSE; |
_SYSTEM_TRIG_ENABLED
Default: TRUE |
If set to FALSE system triggers will not fire |
Range of values TRUE | FALSE
alter session set "_system_trig_enabled"=FALSE; |
_TRACE_FILES_PUBLIC
Default: FALSE |
Sets the file protection mask to 644 |
Range of values TRUE | FALSE
alter session set "_trace_files_public"=TRUE; |
_UNNEST_SUBQUERY
Default: TRUE |
_unnest_subquery = FALSE |
Range of values TRUE | FALSE
EXPLAIN PLAN FOR
SELECT srvr_id
FROM servers
WHERE srvr_id IN (
SELECT srvr_id
FROM serv_inst);
SELECT * FROM TABLE(dbms_xplan.display);
alter session set "_unnest_subquery"=FALSE;
EXPLAIN PLAN FOR
SELECT srvr_id
FROM servers
WHERE srvr_id IN (
SELECT srvr_id
FROM serv_inst);
SELECT * FROM TABLE(dbms_xplan.display); |