Requirements to the data structure

Import and export procedures, as well as postprocessing procedures, are based on the following principles and assumptions.

Each table of geo database Oracle ArcSDE containing the spatial objects of a certain layer of DTM has the required fields:

-  OBJECTID – the identifier of the record;

-  SHAPE – spatial data (metric) of the object;

-  MADOITUONG – the type of the object that defines its conventional sign;

-  SOPHIENHIEUMANHBANDO – nomenclature of the sheet.

Each table of the geo database ArcSDE Oracle must necessarily be correctly registered in the geo database ArcSDE Oracle with mandatory indication of the correct SRID code corresponding to the code EPSG.

If you use SRID codes that do not directly point to the coordinate system in the database EPSG (when the SRID code is not equal to the code EPSG), you must be able to recalculate the metric with such SRID codes to the standard coordinate systems registered in the database EPSG using the geo database.

It is not recommended to use tables with different SRID codes for spatial data fields in one geo database. If you still need to have tables with different SRID codes in the same geo database, the database must be configured in such way that the resources of the database itself can be recalculated between the coordinate systems corresponding to the specified SRID. That is, there should be an opportunity at the level of the query SQL to the database to perform the transformation of one layer of DTM to another layer of DTM having a different coordinate system.

The belonging of an object to a specific layer of DTM is determined by the short name of the object specified in the digital classifier of the map. The short name of the object in the classifier must match the table name in the geo database ArcSDE Oracle, which is responsible for storing the data of a certain layer of DTM.