Extract Families

Administrator User Guide

Multiwrite Databases and Extracts : Extract Families

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.

A Master DB may have up to 191 extract DBs. You can create an extract from another extract, forming a hierarchy of extracts. All the extracts derived from the same master are described as an Extract Family.

The extracts immediately below an extract, are known as Extract Children.

If a hierarchy of extracts is created, the parent extracts for an extract, 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:


PIPE	is the Master and the Parent of PIPE_X1
PIPE_X1	is a Child of PIPE and the Parent of PIPE_X10
PIPE_X10	is a Child of PIPE_X1

The Children of PIPE are PIPE_X1 and PIPE_X2.

PIPE and PIPE_X1 are the Ancestors of PIPE_X10.

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

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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.

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The user must select an MDB containing the extract.

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Data Access Control can be applied.

Extract families enable several users' work to be combined into another higher-level extract, which can then be approved before updating the master.