=head1 NAME

UR::Manual::SchemaDesign - Tips for designing an efficient schema for UR

=head1 Relational Databases

=over 4

=item Avoid creating a table called 'type' or 'types'.

When 'ur update classes' translates it into a class name, it will become
YourNamespace::Type.  Class names ending in '::Type' are reserved for
class metadata, the class will be renamed to 'YourNamespace::TypeTable' to
avoid the conflict.  The table_name for that class will still refer to
the actual table name.  'ur update classes' will print a warning if this
happens, and rename the class automatically.

=item Avoid columns named 'id'

UR expects an object to be uniquely identified by a property called 'id'.
Classes cannot have multiple ID properties where one of them is called 'id',
because 'id' would no uniqiely identify one of them.  If you want to call
the column 'id', then the property name in the class metadata must be 
something else ('id_id', for example) in both the 'has' and 'id_by' sections,
and the column_name set to 'id'.

=item Indexes for common queries

Create indexes in your database to cover common queries.  If you routinely
make queries involving non-primary keys, creating an index that includes
these other columns will improve query times.