Comparisons between Object-Oriented and Relational Databases

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Comparisons between Object-Oriented and Relational Databases
in place September 22, 2000, last modified September 22, 2000

Data Schema in Object-Oriented Database

CREATE CLASS PART
(part_id CHAR(10))

CREATE CLASS ASSY_PART AS SUBCLASS OF PART
(components PART)

CREATE CLASS ATOMIC_PART AS SUBCLASS OF PART
(mfg_proc_ord MFG_PROC)

CREATE CLASS MFG_PROC
(tool_order TOOL)

Data Schema in Relational Database

CREATE TABLE ASSY_PART
(part_id CHAR(10),)

CREATE TABLE COMPONENT
(parent CHAR(10),
child CHAR(10))

CREATE TABLE ATOMIC_PART
(part_id CHAR(10),
mfg_proc_order SET(CHAR(10)))

CREATE TABLE MFG_PROC
(mfg_proc_order CHAR(10),
tool_order SEQUENCE(CHAR(10)))

Query Specification in Object-Oriented Database

SELECT  assy_part.part_id,
        assy_part.part.components.mfg_proc_order.tool_id,
        assy_part.part.components.mfg_proc_order.tool_time,
FROM    assy_part
WHERE   
        assy_part.part_id = 'ASSY-1';

Query Specification in Relational Database

SELECT  assy_part.part_id, atomic_part.part_id, tools.tool_id, tool_time
FROM    assy_part, components, atomic_part, mfg_order, tool_order, tools
WHERE
        assy_part.part_id = 'ASSY-1' AND
        components.part_id = assy_part.part_id AND
        mfg_order.part_id = components.sub_part_id AND
        tool_order.tool_id = tools.tool_id;

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