||Oracle Replication Tips by
Oracle Materialized View Log tablespace
You should always designate the tablespace to create the
log. If you do not specify a tablespace, the Materialized View
log’s tablespace will default to the SYSTEM tablespace.
Some changes to the base table can invalidate materialized views,
particularly if the log is created using ROWID. Like indexes, if
the base table is rebuilt using the ALTER TABLE MOVE
command, the relationship between row IDs and actual rows is
changed, invalidating both indexes and materialized views based on
that table. In this case, all of the table’s indexes would have to
be rebuilt, and a complete refresh on the materialized view would
have to be executed. Similarly, if the master site database ever
requires recovery, it is recommended that all replicated
materialized views be completely refreshed.
Each replicated base table can have only one materialized view log.
If the base table is replicated to multiple remote locations, all of
the remote materialized views will refresh from the same
log, in addition to any local materialized views using the base
Updates, inserts, and deletes on the base tables cause changes in
the row information to be placed in the materialized view logs. As
each remote materialized view refreshes, it will pull the
information from the logs it needs to update itself. Once all
remote sites have refreshed, the old data is removed from the
materialized view log.
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