Reverse engineering also enables creation in HOPEX of physical properties on objects of a database.

Physical properties are parameters enabling expression, for a relational object (table, index, etc.), of the way in which information will be stored within a database. These parameters are specific to each DBMS and can evolve depending on versions of the same DBMS.

See also Adding Physical Properties to Database Objects.

Certain DBMS properties are automatically reversed in HOPEX even if they have not been explicitly specified.

So as not to recover these values by default, HOPEX provides for each DBMS and for each DBMS version a generic clause that contains the list of these default values and treating them specifically.

At reverse engineering, DBMS properties with values equal to values defined in the generic clause are not imported.

You can activate the generic clause by importing into HOPEX the .mol file associated with each DBMS in the Mega_Std folder of your installation.

At reverse engineering of objects in HOPEX, certain physical properties that have not been clearly determined are automatically regenerated by the DBMS via an inheritance mechanism.

With Oracle for example, the value of property PCTFREE in a table, if it has not been specified, is directly inherited from that of its attached tablespace. Such a value is called transverse, since it is derived from an inheritance between two distinct object types. A value is said to be redundant if inheritance is derived from objects of the same type.

At reverse engineering, HOPEX does not recover transverse and redundant values.

Only the management of redundant values can be customized.

In certain cases, reverse engineering of object physical properties requires an ODBC connection with DBMS Administrator rights. For example with Oracle, reverse engineering of the physical properties of tablespaces requires that you use a "System" account.

Reverse engineering of a cluster in Oracle is carried out correctly if the connecting user verifies one of the two following conditions:

If the cluster is not accessible, it is not reversed.

When the user sees the cluster but is neither owner nor administrator, the cluster is reversed, but the link between columns of the cluster and columns of the attached tables is not reversed in HOPEX.