Array database internals

After huge amount of big scientific data, which needed to be stored and processed, has emerged, the problem of large multidimensional arrays support gained close attention in the database world. Devising special database engines with support of array data model became an issue. Development of a well-organized database management system which stands on completely uncommon data model required performing the following tasks: formally defining a data model, building a formal algebra operating on objects from the data model, devising optimization rules on logical level and then on the physical one. Those tasks has already been completed by creators of different array databases. In this paper array formalization, core algebra and optimization techniques are revised using examples of AML, RasDaMan, SciDB - developed array database management systems with different algebras and optimization approaches.