Relational data modeli ng has several weaknesses. It shreds the data in a business entity into mul tiple tables. Queries and views must be used to reconstitute business entities, and this slows performance and complicates development because no rmalized data does not match the business-defined objects in applications. Sparse data is hard to represent in relational models. Complex relationship s (such as networks and hierarchies of data) are hard to represent and are slow to query. Search is difficult because data shredded into tables delibe rately removes context.
\nDocument modeling combined with graph model ing solves these problems and creates a powerful new data modeling paradigm . A document naturally represents a business entity with all its core one-t o-many and many-to-many relationships embedded in the document. This greatl y speeds query performance and simplifies development because the data in t he database directly matches the business-defined objects in applications.< /p>\n
JSON is the core data model of web services, and JSON is a document model. Document databases can directly store and retrieve JSON without mod ification, which makes web services very easy to develop. Document modeling by itself is insufficient, though, because we still need to express relati onships between business entities.
\nGraph modeling enables documents (i.e. business entities) to be related to each other and to transaction en tities. The graph model turns relationships into explicit data (as opposed to implicit foreign keys in the relational model). This makes the relations hips themselves queryable and it makes it possible to query for patterns in the relationships, such as a mother of a father is a grandmother, and so i s the mother of a mother. It also enables your code to traverse graphs to f ind complex patterns and make complex decisions quickly.
\nCombining document modeling with graph modeling creates a document-graph model. This is similar to a property graph model, except that it is much more powerful. A property-graph model is limited to relating a flat list of properties in one entity to a flat list of properties in another entity. The problem is that a business entity is too complex to be represented as a flat list of p roperties. The document-graph model enables you to connect true business en tities to each other and to their transactions in any way imaginable. This class will show you how to do document-graph modeling. Several databases ma ke this document-graph modeling possible including Oracle, Cassandra, MarkL ogic, and OrientDB. You can also combine different databases to make this p ossible, such as combining MongoDB and Neo4J.
\n DTSTART:20180422T143000 SUMMARY:Data Modeling for Document and Graph NoSQL Databases: Part 1 - Intr oduction DTEND:20180422T174459 LOCATION: See Description END:VEVENT END:VCALENDAR