4.3. Data preparation
From the perspective of data preparation efficiency, database
schemas design in the three approaches does not involve
the preparatory steps required in conventional relational
databases which include the definition of database table headers,
data normalization, definition of primary keys and foreign
keys and the creation of relationships between tables. Hence,
clinical data can be imported directly into the databases
“as-is”, without the need to transform the data in order
to fit them into relational schemas. Furthermore, approach
III is more advantageous than approach I & II since native
XML databases provide further convenience by enabling XML
files to be processed in its native form without the need to
import them into the database tables. This can potentially
save a significant amount of time to import large datasets.
Hence, the entire relational schema design process in traditional
relational databases is not required for NoSQL and XML
databases, considerably reducing the effort of database development.