TY - JOUR

T1 - Color coding ER-diagrams, one approach to modeling semistructured data.

T2 - Entity-Relationship diagrams used for aggregate oriented databases.

AU - Lassen, Anders

AU - Ejstrup,, Carsten

PY - 2020/6

Y1 - 2020/6

N2 - Abstract: Aggregate oriented databases[26] support collections of documents with unstructured data. The unstructured markup means that anything can be stored anywhere. Notations for conceptual modeling of entity relationship diagrams have been extended with notation for aggregation, which satisfy the nesting of structures in aggregate oriented databases [11]. Conceptual modeling of ER-diagrams [5,27] has the benefit that a generic diagram of the whole database is sufficient for moving forward to a design activity, while conceptual modeling of aggregate oriented databases has established a notation for modeling [2]. However the model is specific and not generic. Solutions that prefer a different nesting needs a separate aggregate data model. Our approach to conceptual modeling does not violate the existing relational constraints and provides an extra conceptual layer where document- structure can be modeled by color coding. We will show that modeling decisions can readily be made and materialized in document views within this notation.In relational database theory, the study of entity sets is based on the understanding of functional dependencies and normalization. It is this theory of the fundamental properties where every attribute is scalar, not composite. To reach first normal form of a relation, all attribute values must contain atomic values only [Date 1990, p 526-527][8]. No composite attributes; no multivalue attributes, found in JSON or XML. By functional decomposition such representations would be split into a number of relations to reach progressive higher normal forms. The outcome of ER diagramming for relational databases is in many cases a database schema of third normal form or BCNF. But for semi- structured databases, not even the first normal form is reached, underlining the necessity for a notation.

AB - Abstract: Aggregate oriented databases[26] support collections of documents with unstructured data. The unstructured markup means that anything can be stored anywhere. Notations for conceptual modeling of entity relationship diagrams have been extended with notation for aggregation, which satisfy the nesting of structures in aggregate oriented databases [11]. Conceptual modeling of ER-diagrams [5,27] has the benefit that a generic diagram of the whole database is sufficient for moving forward to a design activity, while conceptual modeling of aggregate oriented databases has established a notation for modeling [2]. However the model is specific and not generic. Solutions that prefer a different nesting needs a separate aggregate data model. Our approach to conceptual modeling does not violate the existing relational constraints and provides an extra conceptual layer where document- structure can be modeled by color coding. We will show that modeling decisions can readily be made and materialized in document views within this notation.In relational database theory, the study of entity sets is based on the understanding of functional dependencies and normalization. It is this theory of the fundamental properties where every attribute is scalar, not composite. To reach first normal form of a relation, all attribute values must contain atomic values only [Date 1990, p 526-527][8]. No composite attributes; no multivalue attributes, found in JSON or XML. By functional decomposition such representations would be split into a number of relations to reach progressive higher normal forms. The outcome of ER diagramming for relational databases is in many cases a database schema of third normal form or BCNF. But for semi- structured databases, not even the first normal form is reached, underlining the necessity for a notation.

KW - Faculty of Science

KW - ER-diagram

KW - conceptual modeling

KW - aggregate-oriented databases

KW - aggregate-oriented data model

KW - entity-relationship modeling

UR - http://www.ijisset.org

M3 - Journal article

VL - 6

SP - 14

EP - 22

JO - International Journal of Innovative Studies in Sciences and Engineering Technology (IJISSET)

JF - International Journal of Innovative Studies in Sciences and Engineering Technology (IJISSET)

SN - 2455-4863

IS - 6

ER -