Page 329 - Data Architecture

Chapter 8.3: The Data Warehouse/Operational Environment Interface
Another variation of the classical ETL interface between the operational environment
and the data warehouse environment is the case where there is a staging area.

Fig. 8.3.4 shows a staging area.

Fig. 8.3.4 Staging area.

There are some very specific cases where a staging area is called for. One of those

instances is the case where data from two or more files must be merged and there is a
timing issue. The data from file ABC are ready for merger at 9:00 am, and the data from
file BCD are not ready for a merger until 5:00 pm in the afternoon. In this case, the data
from file ABC must be “staged” until the merge is ready to occur.

A second case for the staging area is where there is a large volume of data and the data
must be separated into different workloads in order to accommodate the parallelization of
the ETL process. In this case, a staging area is needed to separate the volume of data.

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