Replication Guide and Reference

Restrictions for running the Capture program

If you perform any of the following actions while a Capture journal job is running, it terminates with message ASN2301 or ASN2201 in the job log:

• Delete the subscription row from the register table.

• Prevent the Capture program from gaining normal access by locking any of the control tables, user space, or user indexes needed for data capturing.

• Delete the user space ASN/QZSNCTLBLK.

• Delete the user index QDPR/QZSNINDEX5.

• Drop the index QDPR/IBMSNAP_UOW_IDX.

• Delete the message queue QDPR/QZSN5.

• Remove a message from the message queue QDPR/QZSN5 or send an extraneous message to the message queue QDPR/QZSN5.

• Attempt to add new rows to the CD tables or the UOW table when the user's storage limit is exceeded.

• Unsuccessfully attempt to allocate memory.

Keeping the Capture program running successfully

To keep the Capture program running, use the following guidelines:

• Use the default system-wide delete-journal-receiver support to prevent deletions of useful journal receivers. See The delete journal receiver exit routine for more information.

  If you choose to manage journal receivers manually, delete journal receivers used for journaling source tables only if you are certain that all the entries on that receiver were processed by the Capture program.

When conditions make capturing data for a particular source table impossible, the Capture program changes the state of the source table from capturing changes to needing a full refresh. (See Table 23 for a list of such conditions.) Other conditions that prevent data capturing for a source table are:

• An ALTER TABLE is performed on the source table or the CD table such that either:

  • A column in the CD table is no longer in the source table.

  • The column in the CD table has different attributes (data type, length) from its counterpart in the source table.

  When you need to perform an ALTER TABLE on the source table, ensure that you remove the subscription and define the source table again. Or you can use the DJRA alter register function to fix the changed data table. If you defined targets, use the DJRA alter register function to fix those target tables as well.

• A lock is placed on the source table or the CD table that prevents the Capture program from accessing the needed information.

[ DB2 List of Books | Search the DB2 Books ]