Filters a database's relations, keeping only the main relations, and those considered ancestors via foreign key references. Foreign key references involving removed relations are also removed.
# S3 method for database
reduce(x, ...)A database, with the auxiliary relations and foreign key references removed.
A database, whose relations are to be filtered.
further arguments passed to or from other methods.
The main relations are considered to be the relations with the largest number of records.
Using rejoin on the database resulting from reduce is
likely to fail or return incomplete results.