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A MiraMon Map (MMM extension)or a file of metadata, relationships and symbolization by default (REL extension) usually contain a set of references to basic files (rasters or vectors) and the visualization characteristics of these files (which could include other files, such as symbolization tables). These references to basic files can be kept by using absolute or relative address with respect to the file that contains these references. MiraMon automatically saves relative addresses. In order for the computer to know where the file or directory is, it is necessary to indicate (in addition to the relative address) another file or directory with an absolute address which reconstructs the absolute address of the first file and can be used to access this file. Therefore, when a map, REL file, , is saved using a relative address, MiraMon analyses the addresses of the files saved in relation to the address of that file and expresses it relatively. For example, if in a file "C:\Maps\Thematics\VegetationP.rel" one has to write "Color_Paleta=C:\Maps\Simbolization\CColorPalette.dbf"what one must write is "Color_Paleta=..\Simbolization\CColorPalette.dbf" The relative address takes up less space, and if the files are moved at the same time, they can still be opened. If a user sees "C:\Maps\Thematic\VegetationP.rel"and another sees "f:\Server\Maps\Thematic\VegetationP.rel"both users can open the file, which would not be possible if it was written "Color_Paleta=c:\Maps\Simbolization\CColorPalette.dbf"When MiraMon reads a relative address the criterion is simple: the address of the file that contains the relative address is used as a reference address (in the previous example the file address "VegetationP.rel" would be used as a reference address for the file address "CColorPalette.dbf "). MiraMon even applies this concept to the contents of the data set fields. Thus, if in a DBF a character type field contains hyperlinks to other files, these can be written in relation to the DBF, and the dataset can be distributed by the Internet. It is also possible to link to other users who see the DBF place in another network unit. Relative addresses do not have any drawbacks except for the brief time needed to split them when writing and the time needed to reconstruct them when reading (however, MiraMon handles this process). Therefore, MiraMon saves relative addresses automatically. However, most computer programs (including some that are widely used and expensive) do not take this precaution. For example, in MS-Access it is possible to link a DBF table to a database in MDB format in the same directory, but the MDB file and the DBF are moved to another directory, MS-Access will not be able to find the linked DBF file, although it is in the same relative position (in this case, in the same directory). Relative addresses also work in UNC addresses (of type \\server\resource). To save the absolute addresses when saving a map, the checkbox "Write absolute paths" must be activated. |