Database Management System Emulation - Information Systems Reengineering, Integration and Normalization - page 233

HOSPITAL

hospname
sequence#
(secondary
indices)

warno
(secondary
indices)

WARD FACILITY

bedident
(secondary
indices)

PATIENT

bedident
sympdate
(secondary
indices)

bedident
trdate
(secondary
indices)

SYMPTOM TREATMNT

Fig. 6.4 Secondary indexed hierarchical schema for the patient information system

Phase II. Relational interface.
Step 2.1. Restructure the schema by adding record identifiers as secondary
indices.
As a result of the schema translation in phase I, we can derive the record identi-
fiers for each segment (except the root segment) as follows:

6HJPHQW7\SH ,GHQWLILHU7\SH 6HFRQGDU\,QGLFHVUHFRUGLGHQWLILHU
:$5' ) $5''2

3$7,(17 ) %(','(17

6<03720 3 %(','(176<03'$7(

75($7017 3 %(','(1775'$7(

)$&,/,7< , +2631$0(6(48(1&(

ZKHUH) IXOO\LQWHUQDOO\LGHQWLILHG3 SDUWLDOO\LQWHUQDOO\LGHQWLILHGDQG,
LQWHUQDOO\XQLGHQWLILHG

The restructured hierarchical database for the patient information system is shown
in Fig. 6.4 :
Step 2.2. Database restructured by adding secondary indices into segments.