Computing aggregate queries in Raster image databases using pre-aggregated data

Concept:

Pre-aggregation is also used in GIS to generalize maps, such as image pyramid and map cache.

OLAP pre-aggregation solves three problems: select View Selection for the view, and overwrite Query Rewriting for the query and maintain view maintenance for the view.

Execution Plan: from SQL to the actual execution scheme of the database, that is, the optimization selection feature of the scheme: the definition of georaster aggregation and pre-aggregation is given, data is classified as internal, overlapping, and contained according to the range of pre-clustered overwrite aggregation query. The preceding three overhead models are proposed to propose an execution plan for overhead. If there is a full match between pre-aggregation and query, pre-aggregation is directly used. If partial matching exists, the overhead model is used for evaluation, select the optimal plan. Note: The index method of rasdaman tile is B-TREE.