Fat edges: A new approach for partial persistence of hierarchical data in a relational database

• Walter Hargassner
• Christian Ernstbrunner
• Josef Pichler

• R. Breu

In this paper we introduce a new approach for storing a partially persistent hierarchical data model - in particular trees - in a relational database. Several approaches exist for storing trees in relational databases as well as for storing version information for retrieving a former version of a particular node. In this paper we first discuss characteristics of these approaches and the problems and limitations by combining these approaches to store partially persistent data structures into a relational database. Furthermore, we describe a new approach that combines some of the characteristics and advantages of existing methods for fast modification of the data as well as for fast access to the data of former versions.