Streams – Capture Process States

Posted By Sagar Patil

The state of a capture process describes what the capture process is doing currently. You can view the state of a capture process by querying the STATE column in the V$STREAMS_CAPTURE dynamic performance view. The following capture process states are possible


INITIALIZING – Starting up.

  1. 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.
  2. DICTIONARY INITIALIZATION – Processing a dictionary build.
  3. MINING (PROCESSED SCN = scn_value) – Mining a dictionary build at the SCN scn_value.
  4. 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.
  5. CAPTURING CHANGES – Scanning the redo log for changes that evaluate to TRUE against the capture process rule sets.
  6. 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.
  7. EVALUATING RULE – Evaluating a change against a capture process rule set.
  8. CREATING LCR – Converting a change into an LCR.
  9. ENQUEUING MESSAGE – Enqueuing an LCR that satisfies the capture process rule sets into the capture process queue.
  10. PAUSED FOR FLOW CONTROL – Unable to enqueue LCRs either because of low memory or because propagations and apply processes are consuming messages slower than the capture process is creating them. This state indicates flow control that is used to reduce spilling of captured messages when propagation or apply has fallen behind or is unavailable.
  11. SHUTTING DOWN – Stopping.

Leave a Reply

You must be logged in to post a comment.

Top of Page

Top menu