Slide 21 of 52
Notes:
OO GIS support highly efficient spatial indexing structures. But as with earlier-generation hierarchical and network databases, ODBMS' biggest performance hit is in processing queries based on the values of objects' attributes. This is not a fundamental problem - the flexibility of the more modern OODBMSs allows an index to be set up on any attribute independent of any other: the index is then an object like any other and can be distributed to local client caches in the normal way.
Some other ways OO-GIS vendors are improving the performance of queries and sorting include:
- clustering an object's components together on the disk
- supporting efficient join indexing techniques originally developed for RDBMSs
in addition to:
- maintaining additional non-spatial indexing structures
