Oracle Data Guard Concepts and Administration Release 2 (9.2) Part Number A96653-02 |
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This chapter describes the views that are used in a Data Guard environment. This is a subset of the views that are available for use in a database. This chapter contains the following sections:
An Oracle database contains a set of underlying views that are maintained by the server and accessible to the database administrator. These fixed views are also called dynamic performance views because they are continuously updated while a database is open and in use, and their contents relate primarily to performance.
Although these views appear to be regular database tables, they are not. These views provide data on internal disk structures and memory structures. You can select from these views, but you can never update or alter them.
Fixed view names are usually prefixed with either V$, or GV$, for example, V$ARCHIVE_DEST
or GV$ARCHIVE_DEST
. The views that are prefixed with DBA_ display all relevant information in the entire database. Standard dynamic performance views (V$ fixed views) store information on the local instance. In contrast, global dynamic performance views (GV$ fixed views) store information on all open instances. Each V$ fixed view has a corresponding GV$ fixed view. DBA_ views are intended only for administrators. They can be accessed only by users with the SELECT_ANY_TABLE
privilege. (This privilege is assigned to the DBA role when the system is initially installed.)
In most cases, the information available in fixed views persists across instance shutdowns. However, certain fixed view information is reset when the instance is shut down; these views are specifically identified in this chapter.
For additional information about views, see Oracle9i Database Reference.
The DBA_LOGSTDBY_EVENTS
view contains information about the activity of the logical standby database system. It can be used to determine the cause of failures that occur when log apply services apply redo logs. This view contains the following columns:
The DBA_LOGSTDBY_LOG
view shows the logs registered for a logical standby database. The view contains the following columns:
Note: The SCN values in this view correlate to the SCN values in the DBA_LOGSTDBY_PROGRESS (Logical Standby Databases Only) view. |
The DBA_LOGSTDBY_NOT_UNIQUE
view identifies tables that have no primary and no non-null unique indexes. Most of the tables displayed in this view are supported because their columns contain enough information to be maintained in a logical standby database. Some tables, however, cannot be supported because their columns do not contain the necessary information. Unsupported tables usually contain a column defined using an unsupported datatype. This view contains the following columns:
The DBA_LOGSTDBY_PARAMETERS
view contains the list of parameters used by log apply services for logical standby databases. This view contains the following columns:
The DBA_LOGSTDBY_PROGRESS
view describes the progress of log apply services on the logical standby database. This view contains the following columns:
Note: The SCN values in this view correlate to the SCN values in the DBA_LOGSTDBY_LOG (Logical Standby Databases Only) view. |
The DBA_LOGSTDBY_SKIP
view lists the tables that will be skipped by log apply services. The DBA_LOGSTDBY_SKIP
view contains the following columns:
The DBA_LOGSTDBY_SKIP_TRANSACTION
view lists the skip settings chosen. This view contains the following columns:
Column | Datatype | Description |
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Transaction ID undo segment number |
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Transaction ID slot number |
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Transaction ID sequence number |
The DBA_LOGSTDBY_UNSUPPORTED
view identifies the schemas and tables (and columns in those tables) that contain unsupported datatypes. Use this view when you are preparing to create a logical standby database. This view contains the following columns:
The V$ARCHIVE_DEST
view describes, for the current instance, all the archived redo log destinations, their current value, mode, and status.
The V$ARCHIVE_DEST
view contains the following columns:
The V$ARCHIVE_DEST_STATUS
view displays runtime and configuration information for the archived redo log destinations.
The V$ARCHIVE_DEST_STATUS
view contains the following columns:
The V$ARCHIVE_GAP
view displays information to help you identify an archive gap. The V$ARCHIVE_GAP
view contains the following columns:
Column | Description |
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Specifies the thread number |
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Specifies the low number of the log |
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Specifies the high number of the log |
The V$ARCHIVED_LOG
view displays archived redo log information from the control file, including archived log names. This view contains the following columns:
The V$DATABASE
view provides database information from the control file. This view contains the following columns:
Column | Description |
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The database identifier that is calculated when the database is created. This identifier is stored in all file headers. |
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Name of the database. |
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Creation date. |
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Change number at open resetlogs. |
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Timestamp of open resetlogs. |
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Change number at prior resetlogs. |
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Timestamp of prior resetlogs. |
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Archive log mode. |
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Last SCN checkpointed. |
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Last SCN archived. |
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The type of control file. Possible values are:
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Control file creation timestamp. |
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Control file sequence number incremented by control file transactions. |
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Last change number in the backup control file. Set to |
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Last timestamp in the backup control file. Set to |
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Indicates if the next database open allows or requires the resetlogs option. |
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The version time. |
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Open mode information. |
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Indicates if and how the database is protected. Possible values are: |
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Displays the aggregated protection mode currently in effect on the primary or standby database. Possible values are: |
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The value of the |
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Number assigned to the database instantiation. |
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Current role of the database; either primary or standby. |
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Highest |
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Specifies if switchover is allowed. This column currently is supported only for use with physical standby databases. Possible values are:
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Protects data from being changed. Possible values are:
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Ensures that LogMiner will have sufficient information to support chained rows and various storage arrangements such as cluster tables. See Oracle9i SQL Reference for additional information about the |
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For all tables with a primary key, ensures that all columns of the primary key are placed into the redo log whenever an update operation is performed. See Oracle9i SQL Reference for additional information about the |
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For all tables with a unique key, ensures that if any unique key columns are modified, all other columns belonging to the unique key are also placed into the redo log. See Oracle9i SQL Reference for additional information about the |
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Redo generation is forced even for |
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Indicates if the Data Guard configuration is being managed by the broker. Possible values are: |
The V$DATAFILE
view provides datafile information from the control file. This view contains the following columns:
The V$DATAGUARD_STATUS
view displays and logs events that would typically be triggered by any message to the alert log or server process trace files.
The V$DATAGUARD_STATUS
view contains the following columns:
The V$LOG
view contains log file information from the online redo logs. This view contains the following columns:
The V$LOGFILE
view contains information about the online redo logs. This view contains the following columns:
The V$LOG_HISTORY
view contains log history information from the control file. This view contains the following columns:
The V$LOGSTDBY
view provides dynamic information about what is happening to log apply services. This view is very helpful when you are diagnosing performance problems during the logical application of archived redo logs to the standby database, and it can be helpful for other problems. The V$LOGSTDBY
view contains the following columns:
The V$LOGSTDBY_STATS
view displays LogMiner statistics, current state, and status information for a logical standby database during SQL apply operations. If log apply services are not running, the values for the statistics are cleared. This view contains the following columns:
The V$MANAGED_STANDBY
view displays current status information for Oracle database server processes related to physical standby databases in the Data Guard environment. The V$MANAGED_STANDBY
view contains the columns shown in the following table; the information does not persist after an instance shutdown.
The V$STANDBY_LOG
view contains the following columns: