4. Maintaining a Distributed Database : Register as Link with Refresh Statement--Refresh Registration : Effects of Register as Link with Refresh
 
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Effects of Register as Link with Refresh
Several situations may arise that will require you to refresh the registration of a local DBMS object.
Where the old schema of the local table is identical to, or is a subset of, the new schema (for example, when a new column is added to the old local table and the table’s creation time remains unchanged), register as link with refresh has the following effects:
All views dependent on the Ingres Star-level table are retained.
The statistics associated with the registration are left intact if the local table has no statistics or its statistics cannot be read because of the local database’s different architecture. Otherwise, statistics from the local database replace existing Ingres Star-level statistics.
Where the local table has been dropped and recreated (shows a new creation time) using the same schema, possibly with new columns at the end, register as link with refresh has the following effect:
All the views dependent on the Ingres Star-level table are retained.
Where the old schema of the local table is different from the new schema, for example, a column has been dropped or a column type has been redefined, then register as link with refresh is not allowed. An error is returned to the user.