Extract Families

A Master DB may have many extract DBs. The user can create an extract from another extract, forming a hierarchy of extracts. The hierarchy can be up to 10 levels deep. The extracts derived from the same master are defined as an Extract Family. The maximum number of extracts at all levels in an extract family is 8191.

The original database is known as the Master database. The Master database is the parent of the first level of extracts. If a more complex hierarchy of extracts is created, the lower level extracts will have parent extracts which are not the master.

The extracts immediately below an extract are known as extract children. The maximum number of extract children is 408.

If a hierarchy of extracts is created, the parent of an extract, and its parents up to and including the Master DB, are known collectively as the Extract Ancestors.

The following diagram illustrates an example of an extract family hierarchy:

In this example:

Note:
The children of PIPES are PIPES_X1 and PIPES-X2. PIPES and PIPES_X1 are the ancestors of PIPES_X10.

Write access to extracts is controlled in the same way as any other database:

• The user must be a member of the Team owning the Extract. Extracts in the same family can be owned by the same team or by different teams.

• The user must select an MDB containing the extract (or containing its parent, if the extract is a working extract).

• Data Access Control can be applied.

• An extract database cannot be opened in a constructor module (such as MODEL) at a satellite unless all its parent extracts are also allocated to that satellite.

  Note:
  At this release, you can only create an extract at the bottom of an extract tree: you cannot insert a new extract between existing generations. At the Hub, you can also create a new master database above the original master.