The Oracle tutorial you are looking at is Oracle Data Warehouse tiered Manager Solution Developer Network Oracle.
SummaryThis paper describes the principles, procedures, limitations of the hierarchical manager, and combines with Oracle Data Warehouse to realize the efficient storage and management of geo-data and the rapid browsing of large-scale data.
Key WordsHierarchical manager Meta Data quick browsing
Preface
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,
Hierarchy 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:
(1) keyword Begin_metadata marks the beginning of the metadata portion of the table.
(2) Each row of metadata contains two elements: keywords and values. All keywords and values are quoted using double quotes.
(3) The level-by-layer refinement table must contain the \isdrilldown keyword, and the value of the keyword must be True.
(4) Each keyword begins with a "\" (backslash).
(5) Meta-data keywords can be nested within the hierarchy. Each layer in the hierarchy is marked with a backslash (\).
(6) metadata includes the \ddmap\componentmaps\ keyword hierarchy. Specify four metadata keywords for each component table in the hierarchy.
The layered diagram of the Hierarchy Manager is shown in Figure 1, as you can see from the diagram, the hierarchical manager consists of two parts: a component table and a layered table, which extracts data from an Oracle Data warehouse to form a layer in the Component table, based on the requirements of the system. Then determine the name of the layer you want to load and the part of the layer, and load it into a layered refinement table. If it is the first time to load, at this time the level of refinement table is a blank layer, in the loading process, the level of refinement of the table constantly for the increase and deletion of the metafile, which will appear in each component table of information displayed in a layer of detail table shown in the layer. This output the required layer, and edit it, because the level of refinement table data is a copy of the component table, you need to save the edited layer to form a thematic map.
The Hierarchy Manager first forms a blank layer, data mining tools are used to extract data from Oracle data warehouses using hierarchical management, and a layer is formed based on the hierarchical manager's metadata rules, in which the layer name and the load portion of the layer that load layer two are determined by responding to events. The corresponding loading level three, four layer of data, in the loading of the same time, formed a variety of thematic maps. Of course, the implementation of the tiered manager function is achieved through GIS components (MapX, MO, AO, etc.) and programming language (VB, VC, Delphi, etc.).
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2. Tiered Manager Development Steps
A tiered manager application requires a lot of setup and preparation. The main steps are summarized as follows:
(1) Get the data for each table that you want to use when layering layer by layer.
(2) Create a new, empty layer refinement table (. tab file) that contains special columns and special meta data. The metadata specifies a layer name for each component table, identifying important column identity columns and header columns in the Component table.
(3) To add the map by layer refinement table. For example, add a layer-by-tier refinement table to the geoset you use, or add layers of detail tables to the map by encoding.
(4) Add user interface elements to the application to respond to layer-by-level refinement events.
(5) Adding code to respond to user-level refinement tools (that is, writing a hierarchy manager).
(6) The code needs to detect the entity that the user has selected, identify the child entities that need to be added and the entities that need to be deleted, and invoke the application to implement hierarchical or summary map entities.
Example analysis
Because of the large amount of remote sensing influence data, it is very difficult to store, manage, analyze and use the graphic part of the data, which needs to store the data with the relational-object database. In order to get useful layer information, reduce load time and improve editing efficiency in graph display, the graphics need to be layered display, that is, the Layered manager technology described earlier. In this paper, using VB as the programming language, MAPX as a GIS component for two development to achieve tiered management technology.
1. Building a tiered Manager
Build a layered table with table structure:
Definition Table
Type Native Charset "WindowsLatin1"
Fields 3
Key Char (32);
Level Char (32);
Label Char (32);
metadata keywords and corresponding values are:
Begin_metadata
"\isdrilldown" = "TRUE"
"\ddmap\componentmaps\one\file" = "TAB_YNP." Tab "
"\ddmap\componentmaps\one\levelid" = "TAB_YNP"
"\ddmap\componentmaps\one\featureidcol" = "3"
"\ddmap\componentmaps\one\featurecaptioncol" = "1"
... (All other component layers have the same keywords and values)
"\ddmap\hierarchymanager\isdll" = "TRUE"
"\ddmap\hierarchymanager\id" = "SomeDLL.dll"
"\ddmap\hierarchymanager\initiallevel" = "TAB_YNP"
End_metadata
2, the implementation of hierarchical manager
Use the Createcustomtool method to implement a layer by step refinement tool, defined as: Map1.createcustomtool Customdrilldownexpandtool, Mitooltypepoint, Midrilldownexpandcursor, Midrilldowncontractcursor, Midrilldowncontractcursor
The toolused event is triggered each time the custom layer refinement tool is used. During the toolused event, you will need
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The Oracle tutorial you are looking at is Oracle Data Warehouse tiered Manager Solution Developer Network Oracle. Executes code that produces a layered refinement behavior. The process is divided into four main steps:
(1) Use methods such as Selectbypoint or searchatpoint to determine the map entity that the user clicks.
(2) determines the set of child entities that should be substituted for the entity clicked by the user. For example, you can use one or more nested case statements to determine which child entities supersede the selected parent entity.
(3) Extracting spatial data. Extracts information from the data warehouse, such as select Goloc form YN, according to the foregoing conditions. TAB_HQ_KC where prix=68
(4) Call the Drilldownaddfeatures method to add the child entities to the map.
(5) Call the Drilldownremovefeatures method to remove the parent entity from the map (the entity that the user clicked).
(6) Edit the display layer and save the edited result.
3. Result analysis
From the results of the example, it can be seen that the Oracle Data Warehouse can store, analyze, manage and output the spatial data conveniently, and the application of data mining technology can access the data flexibly without loading all the data in the whole data table. The application of Layered manager realizes the large range of spatial data and the overlay of different theme layers, which is very convenient to use in practical applications.
Conclusion
It is one of the difficult problems to make use of the existing mass data efficiently. Oracle Data Warehouse Technology is a technology dedicated to the management and application of massive data, which has obvious advantages in object-relational database, powerful DBMS and support visual retrieval. The theory of geo-Data Warehouse has been perfected in this year's time application, this paper combines theory with practical application in Data Warehouse storage, analysis and expression layer, combined with two development of hierarchical management GIS, develops hierarchical management system based on Oracle Data Warehouse, which combines the advantages of data warehouse and layered management, A useful attempt has been made in the application of geo-spatial data.
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