Abstract This paper describes the principles, procedures, limitations of the hierarchical manager, and combines with Oracle Data Warehouse to realize the effective storage, management of geo-data and rapid browsing of large range of data.
keyword hierarchical manager meta Data quick browsing
Objective
The 21st century is the century of information, the competition of the comprehensive national strength is to a great extent the information competition, and the information utilization ratio competition. In recent years, with the development and implementation of "Digital Earth" and "digital land" strategy, the massive data of geoscience has been increasing rapidly, and the data storage, analysis, management and processing become more and more complicated. With the maturity of Oracle technology, especially the appearance of 8.15 Oracle spatial, data Warehouse has incomparable advantages in mass data storage, analysis and expression. At the same time, due to the huge amount of information, traditional data storage and display methods in a large range of data fast browsing, it is necessary to change the spatial data storage mode, loading the required space data parts, to avoid unnecessary data repeatedly loading and unloading.
Hierarchy Manager
1. Hierarchical Manager Architecture
Tiered manager is a key part of fast browsing for large scale data, it controls the structure and metadata definition and assignment of the level-by-layer thinning table, defines the key information in the Component table, and gives the sources of spatial data, data mining rules, layer loading range and graphic editing, outputting and saving. The Hierarchy Manager consists of two parts:
A a set of spatial data tables stored in an Oracle Data warehouse for layering each detail layer in a layer, called a component table;
b An empty table that contains the structure definition of the table and the special metadata that describes the component table, which is called a layered refinement of the table. Any tier-by-layer refinement of the application requires a layer-by-level refinement of the table to understand the hierarchical keyword descriptions of layers in layers of refinement, and the hierarchical association between them. When you are layering, the Hierarchy manager, as part of your program, determines the layer and its keywords that you want to add to the child entities to determine which entity information you want to add and remove in layers.
Layer refinement layer is a special map layer, which has its own table structure of the blank layer, and the metadata for all the load layer rules and restrictions, the display of map information is according to the rules of the metadata from other tables or databases extracted. When you show layers of refinement in a map, the Hierarchy Manager creates a temporary table and then copies the entities from the Component table to the temporary table. The entities that are displayed in the layers refinement layer are actually copies of the entities in the Component table. This allows you to flexibly load the required information on the layer. When the application terminates, the temporary table is discarded, and the extracted layer can be saved in order to save useful thematic map information. At this point, if the user looks at the layer information, the layers of refinement will still be a single layer.
The requirement of tier-by-layer refinement, as the organizational core of the hierarchy Manager, defines metadata keywords and three standard columns: keywords, layers, and labels. and has its own set of grammars: