V$XSTREAM_CAPTURE

V$XSTREAM_CAPTURE displays information about each capture process that sends LCRs to an XStream outbound server.

Note:

This view does not display information about capture processes that send LCRs to Oracle Streams apply processes. To view information about such capture processes, query the V$STREAMS_CAPTURE view.
Column Datatype Description
SID NUMBER Session identifier of the capture process
SERIAL# NUMBER Session serial number of the capture process session
CAPTURE# NUMBER Capture process number. A capture process is an Oracle background process prefixed by cp
CAPTURE_NAME VARCHAR2(30) Name of the capture process
LOGMINER_ID NUMBER Session ID of the Oracle LogMiner session associated with the capture process
STARTUP_TIME DATE Time when the capture process was last started
STATE VARCHAR2(551) State of the capture process:
  • INITIALIZING - Starting up.

  • WAITING FOR DICTIONARY REDO - Waiting for redo log files containing the dictionary build related to the first SCN to be added to the capture process session. A capture process cannot begin to scan the redo log files until all of the log files containing the dictionary build have been added.

  • DICTIONARY INITIALIZATION - Processing a dictionary build.

  • MINING (PROCESSED SCN = scn_value) - Mining a dictionary build at the SCN scn_value.

  • LOADING (step X of Y) - Processing information from a dictionary build and currently at step X in a process that involves Y steps, where X and Y are numbers.

  • CAPTURING CHANGES - Scanning the redo log for changes that satisfy the capture process rule sets.

  • WAITING FOR REDO - Waiting for new redo log files to be added to the capture process session. The capture process has finished processing all of the redo log files added to its session. This state is possible if there is no activity at a source database. For a downstream capture process, this state is possible if the capture process is waiting for new log files to be added to its session.

  • EVALUATING RULE - Evaluating a change against a capture process rule set.

  • CREATING LCR - Converting a change into an LCR.

  • ENQUEUING MESSAGE - Enqueuing an LCR that satisfies the capture process rule sets into the capture process queue.

  • PAUSED FOR FLOW CONTROL - Unable to enqueue LCRs either because of low memory or because propagations and outbound servers are consuming messages slower than the capture process is creating them. This state indicates flow control that is used to reduce spilling of captured LCRs when propagation or apply has fallen behind or is unavailable.

  • WAITING FOR THE BUFFERED QUEUE TO SHRINK - Waiting for the buffered queue to change to a smaller size. The buffered queue shrinks when there is a memory limitation or when an administrator reduces its size.

  • WAITING FOR n SUBSCRIBER(S) INITIALIZING - Waiting for outbound servers that receive LCRs from the capture process to start, where n is the number of apply processes.

  • WAITING FOR TRANSACTION - Waiting for LogMiner to provide more transactions.

  • WAITING FOR INACTIVE DEQUEUERS - Waiting for the capture process's queue subscribers to start. The capture process stops enqueuing LCRs if there are no active subscribers to the queue.

  • SUSPENDED FOR AUTO SPLIT/MERGE - Waiting for a merge operation to complete.

  • SHUTTING DOWN - Stopping.

  • ABORTING - Aborting.

TOTAL_PREFILTER_DISCARDED NUMBER Total number of prefiltered messages discarded
TOTAL_PREFILTER_KEPT NUMBER Total number of prefiltered messages kept
TOTAL_PREFILTER_EVALUATIONS NUMBER Total number of prefilter evaluations
TOTAL_MESSAGES_CAPTURED NUMBER Total number of redo entries passed by LogMiner to the capture process for detailed rule evaluation since the capture process last started. A capture process converts a redo entry into a message and performs detailed rule evaluation on the message when capture process prefiltering cannot discard the change.
CAPTURE_TIME DATE Time when the most recent message was captured
CAPTURE_MESSAGE_NUMBER NUMBER Number of the most recently captured message
CAPTURE_MESSAGE_CREATE_TIME DATE Creation time of the most recently captured message
TOTAL_MESSAGES_CREATED NUMBER Count associated with ELAPSED_LCR_TIME to calculate rate
TOTAL_FULL_EVALUATIONS NUMBER Count associated with ELAPSED_RULE_TIME to calculate rate
TOTAL_MESSAGES_ENQUEUED NUMBER Total number of messages enqueued since the capture process was last started
ENQUEUE_TIME DATE Time when the last message was enqueued
ENQUEUE_MESSAGE_NUMBER NUMBER Number of the last enqueued message
ENQUEUE_MESSAGE_CREATE_TIME DATE Creation time of the last enqueued message
AVAILABLE_MESSAGE_NUMBER NUMBER For local capture, the last redo SCN flushed to the log files. For downstream capture, the last SCN added to LogMiner through the archived redo log files.
AVAILABLE_MESSAGE_CREATE_TIME DATE For local capture, the time the SCN was written to the log file. For downstream capture, the time the most recent archived redo log file (containing the most recent SCN) was added to LogMiner.
ELAPSED_CAPTURE_TIME NUMBER Elapsed time (in hundredths of a second) scanning for changes in the redo log since the capture process was last started
ELAPSED_RULE_TIME NUMBER Elapsed time (in hundredths of a second) evaluating rules since the capture process was last started
ELAPSED_ENQUEUE_TIME NUMBER Elapsed time (in hundredths of a second) enqueuing messages since the capture process was last started
ELAPSED_LCR_TIME NUMBER Elapsed time (in hundredths of a second) creating LCRs since the capture process was last started
ELAPSED_REDO_WAIT_TIME NUMBER Elapsed time (in hundredths of a second) spent by the capture process in the WAITING FOR REDO state
ELAPSED_PAUSE_TIME NUMBER Elapsed flow control pause time (in hundredths of a second)
STATE_CHANGED_TIME DATE Time at which the state of the capture process changed
SGA_USED NUMBER The total amount of shared memory (in bytes) currently used by the capture process out of the amount allocated (SGA_ALLOCATED)
SGA_ALLOCATED NUMBER The total amount of shared memory (in bytes) allocated from the Streams pool for the capture process
BYTES_OF_REDO_MINED VARCHAR2(64) The total amount of redo data mined (in bytes) since the capture process last started
SESSION_RESTART_SCN VARCHAR2(64) The SCN from which the capture process started mining redo data when it was last started

Note:

The ELAPSED_CAPTURE_TIME, ELAPSED_RULE_TIME, ELAPSED_ENQUEUE_TIME, ELAPSED_LCR_TIME, and ELAPSED_REDO_WAIT_TIME columns are only populated if the TIMED_STATISTICS initialization parameter is set to true, or if the STATISTICS_LEVEL initialization parameter is set to TYPICAL or ALL.

Note:

The V$XSTREAM_CAPTURE view is available starting with Oracle Database 11g Release 2 (11.2.0.2)