Oracle9i Data Guard Broker Release 2 (9.2) Part Number A96629-01 |
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Database resource properties help you to view and control the behavior of database resource objects, log transport services, and log apply services in a broker configuration. This chapter provides the following sections about the monitorable and configurable properties:
Section 8.1, "Monitorable (Read-Only) Properties for Database Resources"
Section 8.2, "Configurable Properties for Database Resources"
Monitorable properties allow you to view information related to resources, but you cannot change the values of these properties. You can view all of the monitorable properties using CLI SHOW
commands.
The following sections describe the database resource monitorable properties:
The InconsistentLogXptProps
monitorable property returns a table that shows all properties related to log transport services whose values are inconsistent between the Data Guard configuration file and the actual value in the database.
Query this property on the primary database resource. The table contains the following columns:
STANDBY_SITE_NAME
The name of the standby site that contains the database resource to which this log transport services property pertains.
PROPERTY_NAME
The name of the log transport services property with an inconsistent value.
DATABASE_VALUE
The corresponding value saved in the database server parameter file.
SPFILE_VALUE
The corresponding value saved in the server parameter file (SPFILE).
METADATA_VALUE
The value of the log transport services property saved in the Data Guard configuration file.
The InconsistentProperties
monitorable property returns a table that shows all database properties whose values contained in the Data Guard configuration file are inconsistent with the actual values in the database, and the values in the corresponding server parameter file (SPFILE) or the runtime values in the database.
Query this property on the each individual database resource. The table contains the following columns:
PROPERTY_NAME
The name of the database property with the inconsistent value.
DATABASE_VALUE
The corresponding runtime value being used in the database.
SPFILE_VALUE
The corresponding value saved in the server parameter file (SPFILE).
METADATA_VALUE
The value of the database property saved in the Data Guard configuration file.
The LogXptStatus
property contains the error status of log transport services for each of the currently enabled standby sites. You query this property on the primary database resource.
The format of the error status is as follows:
"standby1_sitename
=error_status,standby2_sitename
=error_status,..."
The error status can be an empty string, which indicates there is no error.
In the following example, the string for Standby1 is empty because there is no error for the Standby1 destination. The standby2 destination returned the ORA-01034
message.
DGMGRL> SHOW RESOURCE VERBOSE 'Sales_db' 'LogXptStatus';
LogXptStatus ='Standby1=,standby2=ORA-01034: ORACLE not available'
Note: In Oracle9i Data Guard Manager, information from the LogXptStatus property is displayed in the Log Transport Summary section of the General property page for the primary database resource. |
The LsbyFailedTxnInfo
property identifies a failed transaction that caused log apply services to stop. This property contains a string with the following values from the DBA_LOGSTDBY_EVENTS
view:
XIDUSN
: Transaction ID undo segment numberXIDSLT
: Transaction ID slot numberXIDSQN
: Transaction ID sequence numberSTATUS_CODE
: Status (or Oracle error code) belonging to the STATUS messageSTATUS
: Description of the current activity of the process, or the reason why log apply services stoppedThe transaction IDs and status information are separated by a string of pound (###) signs.
The LsbyParameters
property contains a string that identifies the MAX_SGA
(maximum system global area) and MAX_SERVERS
(maximum number of parallel query servers) specifically reserved for log apply services. The value contains the following information, separated by the "###" string:
The LsbySkipTable
property returns a table with following columns from the DBA_LOGSTDBY_SKIP
view:
ERROR
Indicates if the statement should be skipped or if errors should be returned for the statement
STATEMENT_OPT
Indicates the type of statement that should be skipped
SCHEMA
The schema name under which this skip option should be used
NAME
Name of the object for which this skip option should be used
PROCEDURE
Name of the stored procedure to execute when processing the skip option
ACTIVE
The table separates the column information with the "###" string.
The LsbySkipTxnTable
property returns a table with following columns:
XIDUSN:
Transaction ID undo segment numberXIDSLT:
Transaction ID slot numberXIDSQN:
Transaction ID sequence numberACTIVE:
Description of the current activity of the process, or the reason why log apply services stoppedThe SbyLogQueue
property returns a table that indicates all logs that were received by the standby site, but have not yet been applied. If no rows are returned, it implies all logs received have been applied. The table contains the following columns in the order shown:
LOG_SEQ
The log sequence number
TIME_GENERATED
The time when the log was generated
TIME_COMPLETED
The time when the log was completed
For example:
DGMGRL> SHOW RESOURCE VERBOSE 'reportingdb' 'SbyLogQueue'; STANDBY_RECEIVE_QUEUE LOG_SEQ TIME_GENERATED TIME_COMPLETED 6 11/21/2000 10:57:16 11/21/2000 10:57:41 7 11/21/2000 10:57:41 11/21/2000 10:57:43 8 11/21/2000 10:57:43 11/21/2000 10:57:49
In Data Guard Manager, this information is displayed on the Log Files property page.
The SendQEntries
property returns a table that shows all log files on the primary site that have not yet been successfully shipped to one or more standby sites. Query this property on a standby database resource. Query this property on the primary database resource. The table contains the following columns:
SITE_NAME
The value can be empty or it can contain the name of the site. If empty, the STATUS
column will contain a value of CURRENT
or NOT_ARCHIVED
.
STATUS
The STATUS
column is set to one of the following values:
CURRENT
: A log file to which online redo is being written currently.NOT_ARCHIVED
: A completed online redo log file that has not been archived locally.ARCHIVED
: A completed log file that has been archived locally but has not been shipped to the standby site specified in the SITE_NAME
column.The table contains exactly one row with the value of STATUS=CURRENT
. There can be multiple rows with the value STATUS=ARCHIVED
or STATUS=NOT_ARCHIVED
.
LOG_SEQ
The log sequence number. Multiple rows may have the same LOG_SEQ
value (for different SITE_NAME
values).
TIME_GENERATED
The time when the log was generated.
TIME_COMPLETED
The time when the log was completed.
For example, the following shows output from a SHOW RESOURCE VERBOSE
command:
DGMGRL> SHOW RESOURCE VERBOSE 'db' 'SendQEntries'; PRIMARY_SEND_QUEUE SITE_NAME STATUS LOG_SEQ TIME_GENERATED TIME_COMPLETED Standby ARCHIVED 9 11/21/2001 10:57:49 11/21/2001 10:59:42 Standby ARCHIVED 10 11/21/2001 10:59:42 11/21/2001 10:59:43 Standby ARCHIVED 11 11/21/2001 10:59:43 11/21/2001 10:59:49 Standby ARCHIVED 12 11/21/2001 10:59:49 11/21/2001 10:59:54 CURRENT 13 11/21/2001 10:59:54
Note: In Oracle9i Data Guard Manager, information from the |
The configurable properties include the following:
See Also:
Section 1.6.3 for more information about database property management |
Updates the ALTERNATE
attribute for the LOG_ARCHIVE_DEST_
n
initialization parameter. With this property, you specify the name of the site to which log transport services should ship archived redo logs in case there is a problem shipping to the current site. The broker also updates the setting of the LOG_ARCHIVE_DEST_STATE_
n
initialization parameter to the specified ALTERNATE
site.
Datatype |
String |
Valid Values |
Site name (except for the primary site and the standby site itself) |
Broker Default |
Empty string |
Imported? |
No |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical and logical |
Corresponds to |
For example, if you are managing a configuration with the CLI you would issue the following SQL statement to set the standby site 'Chicago' to be an alternate site for the standby site 'San Francisco' with database 'reportingdb':
SQL> ALTER RESOURCE 'reportingdb' ON SITE 'San Francisco' SET PROPERTY > 'Alternate' = 'Chicago';
Specifies the number of archived redo logs that log apply services should apply immediately to the physical standby database, temporarily overriding any previously specified apply delay interval. The ApplyNext
property value is applied only at the point when you explicitly specify that value. Once the value is applied, the property no longer has any effect until the next time that its value is explicitly specified.
Specifying a value for this property has no effect and will be ignored if management of the standby database is disabled or if the log apply services are offline at the time that a value is specified.
Specifies whether or not to cancel the delay option that has been set on the primary database or on the standby database:
ApplyNoDelay=YES
, then log apply services apply the archived redo logs as soon as they have been archived to the standby site. This property is equivalent to using the following SQL statement:
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE NODELAY;
ApplyNoDelay=NO
, then log apply services respect the delay settings specified by the DelayMins property of the standby database. This property is equivalent to using the following SQL statement:
ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DEFAULT DELAY;
The value of the ApplyNoDelay
property persists through role changes. For example, if the ApplyNoDelay
property is set to Yes and then the site undergoes a series of switchover operations, transitioning the database from the standby role to the primary role and then back again, the ApplyNoDelay
property will continue to be set to Yes throughout all of the role changes.
Specifies the number of concurrent processes log apply services can use on the physical standby database for managed recovery. If log apply services are offline, then setting the property has no immediate effect. However, when log apply services are online again, the value of the property is used to determine the mode of log apply services.
Updates the ARCHIVE_LAG_TARGET
initialization parameter setting. This property 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 amount of time you specify (in seconds) elapses. That way, the standby database will not miss redo records generated from a time range longer than the value set for the ARCHIVE_LAG_TARGET
initialization parameter.
Specifies the size of the SGA buffer to be used when network I/O operations are to be done asynchronously using the log writer process (LGWR). The value you set for AsyncBlocks
property takes effect only when the LogXptMode
property is set to ASYNC
.
Datatype |
Integer |
Valid Values |
0 to 20,480 blocks |
Broker Default |
2048 |
Imported? |
Yes, from the |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical and logical |
Corresponds to |
Specifies whether or not the standby destination is mandatory or optional.
Datatype |
String |
Valid Values |
|
Broker Default |
|
Imported? |
Yes, from the |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical and logical |
Corresponds to |
Distinguishes standby datafile filenames from primary datafile filenames. You must set this property on all standby databases. If you add a datafile to the primary database, you must add a corresponding file to the standby database. When the standby database is updated, this property converts the datafile name on the primary database to the datafile name on the standby database. The file on the standby database must exist and be writable, or the recovery process will halt with an error.
Specifies the number of minutes log apply services will delay applying the archived redo logs on the standby database.
Specifies the dependency
attribute for the LOG_ARCHIVE_DEST_
n
parameter. The site name (can be the primary or a standby site name) on which this site depends for receiving archived redo logs.
Datatype |
String |
Valid Values |
Site name, except for the standby site itself or you can set this property to null. |
Broker Default |
Empty string |
Imported? |
No |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical or logical |
Corresponds to |
Dependency attribute for the |
Specifies the format for filenames of archived redo log files.
Specifies the number of archiver background processes (ARC0 through ARC9) the Oracle database server initially invokes. The actual number of archiver processes in use may vary subsequently based on archive workload.
Defines the minimum number of destinations that must succeed for the online log file to be available for reuse.
Set this parameter to an integer value to see the progression of the archiving of redo logs on the primary and the standby sites. Oracle database server writes an audit trail of the archived logs received from the primary database into a trace file.
Converts the filename of a new log file on the primary database to the filename of a log file on the standby database. If you add a log file to the primary database, you must add a corresponding file to the standby database.
Specifies whether or not log transport services can send archived redo logs to the particular standby database. The broker uses the value of the LogShipping
property only when the primary database is in READ-WRITE-XPTON state:
LogShipping
property is set to on or off.LogShipping
property is ON
, then log transport services are enabled to send archived redo logs to the particular standby site. If the LogShipping
property is OFF
, then log transport services are disabled to send archived redo logs to the particular standby site.
Datatype |
String |
Valid Values |
ON or OFF |
Broker Default |
ON |
Imported? |
No |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical and logical |
Corresponds to |
The ENABLE and DEFER values for the LOG_ARCHIVE_DEST_STATE_n initialization parameter |
Allows you to set the data protection mode for log transport services. You set the log transport services on each standby database to one of the following modes:
SYNC
Configures the log transport services to this standby using the LGWR
, SYNC
, AFFIRM
settings. If this is a physical standby database, standby redo logs are required. If this is a logical standby database, standby redo logs are not required because logical standby databases do not use them. This mode provides the highest grade of data protection and potentially a correspondingly high impact on primary database performance.
ASYNC
Configures the log transport services to this standby using the LGWR
, ASYNC
, NOAFFIRM
settings. Also, standby redo logs are required for physical standby databases; they are not required for logical standby databases. This mode provides the next highest grade of data protection with a correspondingly lower impact on primary database performance.
ARCH
Configures the log transport services to this standby database using the ARCH
setting. Standby redo logs are not required. This is the default setting.
This mode provides the lowest grade of data protection and the least impact on primary database performance of the 3 options.
Datatype |
String |
Valid Values |
SYNC or ASYNC or ARCH |
Broker Default |
|
Imported? |
Yes, from the ARCHIVER, TRANSMIT_MODE, AFFIRM column of V$ARCHIVE_DEST view |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical or logical |
Corresponds to |
ARCH, LGWR, SYNC, ASYNC, AFFIRM, NOAFFIRM attributes for the LOG_ARCHIVE_DEST_n initialization parameter. ARCHIVER, TRANSMIT_MODE, AFFIRM column of V$ARCHIVE_DEST view |
See Also:
Chapter 4 for more information about setting data protection modes for log transport services |
Provides a way to apply specific SQL statements and skip (ignore) SQL statements that you do not want applied to the logical standby database. The SKIP
procedure:
This property is used only when you explicitly update its value. The property will not be reused when you enable the database for management by the broker.
.
Note: Data Guard Manager uses the |
Provides criteria to determine if an error should cause log apply services to stop. All errors to be skipped are stored in system tables that describe how exceptions should be handled. This property is used only when you explicitly update its value. The property will not be reused when you enable the database for management by the broker.
.
Note: Data Guard Manager uses the |
Skips over a transaction that caused the log apply services to stop applying transactions to the logical standby database. This property allows you to specify the transaction ID (XIDSQN NUMBER
) of the problematic transaction that you want log apply services to ignore. Before you restart log apply services, you should take some corrective action, such as providing a compensating transaction. This will help avoid data divergence between the primary and logical standby databases that might result from skipping the problematic transaction. This property is used only when you explicitly update its value. The property will not be reused when you enable the database for management by the broker.
Note: Data Guard Manager uses the |
Reverses the actions of the LsbyASkipCfgPr property by finding the record, matching all the parameters, and removing the record from the system table. The match must be exact, and multiple skip actions can be undone only by a matching number of unskip actions. You cannot undo multiple skip actions using wildcard characters. The property will not be reused when you enable the database for management by the broker.
.
Note: Data Guard Manager uses the |
Reverses or undoes the actions of the LsbyASkipErrorCfgPr property by finding the record, matching all of the parameters, and removing the record from the system table. The match must be exact, and multiple skip actions can be undone only by a matching number of unskip actions. You cannot undo multiple skip actions with just one unskip procedure call. The property will not be reused when you enable the database for management by the broker.
.
Note: Data Guard Manager uses the |
Reverses the actions of the LsbyASkipTxnCfgPr property. The transaction IDs must match exactly, and multiple skip transaction actions can be undone only by a matching number of unskip transaction actions. You cannot undo multiple skip transaction actions with just one unskip transaction procedure call. The property will not be reused when you enable the database for management by the broker.
.
Note: Data Guard Manager uses the |
Specifies the number of events that will be stored in the DBA_LOGSTDBY_EVENTS
table, which stores logical standby event information.
Specifies the number of megabytes for the system global area (SGA) allocation for log apply services cache. The default value is one quarter of the value set for the SHARED_POOL_SIZE
initialization parameter.
Specifies the number of parallel query servers specifically reserved for log apply services. By default, log apply services use all available parallel query servers to read the log files and apply changes.
Controls whether or not DDL statements that have been applied to the logical standby database are recorded in the DBA_LOGSTDBY_EVENTS
table. Specify one of the following values:
TRUE
: Indicates that DDL statements applied to the logical standby database are recorded in the DBA_LOGSTDBY_EVENTS
table. This is the default parameter setting.FALSE
: Indicates that applied DDL statements are not recorded.
Controls whether or not skipped DDL statements are recorded in the DBA_LOGSTDBY_EVENTS
table. Specify one of the following values:
TRUE
: Skipped DDL statements are recorded in the DBA_LOGSTDBY_EVENTS
table. This is the default parameter setting.FALSE
: Skipped DDL statements are not recorded in the DBA_LOGSTDBY_EVENTS
table.
Controls whether skipped errors (as described by the DBMS_LOGSTDBY.SKIP_ERROR
procedure) are recorded in the DBA_LOGSTDBY_EVENTS
table. Specify one of the following values:
TRUE
--Skipped errors are recorded in the DBA_LOGSTDBY_EVENTS
table.FALSE
--Skipped errors are not recorded in the DBA_LOGSTDBY_EVENTS
table.
Level of transaction consistency maintained between the primary and standby databases. Specify one of the following values:
FULL
: Transactions are applied to the logical standby database in the exact order in which they were committed on the primary database. This option results in the lowest performance.READ_ONLY
: Transactions are committed out of order (which provides better performance), SQL SELECT
statements return read-consistent results. This is particularly beneficial when the logical standby database is being used to generate reports. Note: DML statements involving standby tables are not allowed in this mode.NONE
: Transactions are committed out of order, and no attempt is made to provide read-consistent results. This results in the best performance of the three modes. If applications that are reading the logical standby database make no assumptions about transaction order, this option works well.
Specifies the maximum number of contiguous archival failures before the log transport services stop trying to transport archived redo logs to the standby database. A value of zero indicates that an unlimited number of failures are allowed.
Datatype |
Integer |
Valid Values |
>=0 |
Broker Default |
0 |
Imported? |
Yes, from the |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical and logical |
Corresponds to |
Specifies the minimum number of seconds before the archiver process (ARCn, foreground, or log writer process) should try again to access a previously failed destination.
Datatype |
Integer |
Valid Values |
>=0 seconds |
Broker Default |
0 |
Imported? |
Yes, from the |
Parameter Class |
Dynamic |
Role |
StandbyFoot 1 |
Standby Type |
Physical and logical |
Corresponds to |
Updates the file specification for the STANDBY_ARCHIVE_DEST
initialization parameter. Specifies the location of archived redo logs arriving from a primary database. You can set this property to null.
Updates the STANDBY_FILE_MANAGEMENT
initialization parameter setting. Set this property on each standby site to indicate whether or not the filenames on the standby database are the same as those used on the primary database. Set this parameter to AUTO
only if the COMPATIBILITY
parameter is set to 9.0.n or higher.
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