Metadata file format and table relations file format

METADATA FILE FORMAT AND TABLE RELATIONS FILE FORMAT

See a correspondence table between the keys of raster and vector older documentation files and the new keys in the REL4 format metadata files.

REL4: Beginning with MiraMon version 4, the REL file (now in REL4 format) is extended and enhanced to a metadata file that contains all the information of the older documentation files and the information in the REL files in REL1 format. This is a Windows INI format file, made up of sections and keys. The order of the sections and the order of the keys within each section is not important for the correct reading of the file. Furthermore, the sections related to the database tables and the relations between the tables has been completely redesigned and extended so that, now, each field can be linked to any number of tables and, simultaneously, each new associated table can, in turn, be associated to an unlimited number of other tables through its fields. This schemes allows for an unlimited number of "floors" and the simultaneous access to different databases. The databases may be in DBF format or any of the formats that support access through the ODBC standard (Acces, Oracle, Infromix, etc).

Since the REL file in REL4 format is a metadata file it may accompany any dataset (whether structured vector or raster). Unstructured vector files can only be documented in the older documentation file (*.dvc) format and REL1 format.
REL1: This file forms part of a family of associated files that make up a structured vector layer in versions of MiraMon previous to version 4.0. It is a plain text file, similar in format to the Windows INI files, containing various pieces of information:

- Information to link the graphical dataset with the alphanumeric dataset and optional descriptions of each field (units, etc.), as well as information about other tables that act as dictionaries. This information is found in the [PRINCIPAL] and the [ASSOCIAT] sections.

- Information on the (default) display properties of the layer and the legend, in the [COLOR_TEXT] and [VISU_LLEGENDA] sections, respectively. See the section "the REL file and the dictionaries in MiraMon versions 1 to 3" in the Appendix "Vector format descriptions" of the MiraMon Manual)

- Information about whether the datasets belong to map series in the [SERIES_CARTO] section. (See the Appendix "Map Series" in the MiraMon Manual for more details.)

This file has a strict format with regards to the sections since the [PRINCIPAL] section must always be at the start of the file, followed by the [ASSOCIAT] sections, which must appear in the same order as the fields.

These REL1 format files are always accompanied by an older documentation file. The REL1 format restricts relations between tables to those tables in DBF format, with just one level of relationships and a single associated table for each field. These limitations are overcome in REL4 format.
"Older documentation files": under this heading are grouped the documentation files which, in versions of MiraMon previous to version 4.0, accompany (vector or image) graphical files. This is a plain text file that can be edited with any type of word processor (NOTEPAD, EDIT, etc) and that includes a minimal description of the layer. In versions 4.0 and above this information is included in the REL files (in REL4 format), which substitute and enhance the older documentation files. The REL file, in format 4, is also a plain text file but, due to its greater complexity, it is recommended to only edit it through the GeM+ interface.

The file extensions of these documentation files are::

- *.doc for raster files
- *.dvc for unstructured vector files
- *.dvt, *.dvn, *.dva, and *.dvp for structured vector files, where the last letter depends on the type of vector objects: points, nodes, arcs and polygons respectively).

The raster and unstructured vector documentation files have a format that is compatible with the Idrisi, v. 4.x. software, but with the enhancements and limitations of MiraMon. (See the MiraMon Manual for more information). However, the older documentation files of structured vector files are always accompanied by an REL1 file.