Oracle Corporation
Hash-based efficient secondary indexing for graph data stored in non-relational data stores

Abstract:

A method and apparatus for a graph database instance (GDI) maintaining a secondary index, that indexes data from a sparse data map storing graph application data, within a sparse data map dedicated to the secondary index. The GDI formulates row-keys, for the secondary index map, by hashing the values of key/value pairs stored in rows of a map storing application data. The GDI stores for each formulated row-key, in the row of the secondary index that is indexed by the formulated row-key, references to rows of the map storing application data that match the key/value pair on which formulation of the row-key was based. The row-keys into the secondary index map may incorporate bucket identifiers, which, for each key/value pair, allows the GDI to spread the references to graph elements that match the key/value pair among a set number of "buckets" for the key/value pair within the secondary index map.