How Export To Interchange File (Coverage) works

NOTE: This tool only works with an ArcInfo license and will only be available in ArcToolbox if you have installed ArcInfo Workstation.

Export creates an ARC/INFO interchange file to transfer coverages; INFO tables; text files, such as AML macros; and other ARC/INFO files between various machine types. An interchange file contains all coverage information and appropriate INFO table information in a fixed-length, ASCII format. It can be fully or partially compressed and decompressed ASCII depending on the Export option used.

There are many ways to use Export. One way is to transport a coverage and its associated INFO tables. This is done using the keyword COVER for the first argument. Another way is to transfer an INFO table. In this case, any INFO pathname/username can be used to specify the INFO table to be exported. This option is invoked by using the keyword INFO for the first argument. Export may be used with the TEXT option to transfer key files, AML macros, and other text files.

Once Export is used, the interchange file can be transferred by tape to another machine where Import can be used to recreate the coverage, INFO tables, text files, and so on.

The Import and Export commands can also be used to back up individual coverages to tape for archiving (as opposed to backing up entire user workspaces). For example, individual coverages corresponding to map library layers within a single tile (for example, map sections) can be archived to tape and restored to disk as needed.

The following is a checklist of what issues must be dealt with when taking an export file from one platform to another:

NOTE: Exporting a grid can result in an export file much larger than the original grid, even when Full compression is used. This is because each grid cell must be represented in the export file in ASCII format, which is less efficient than the grid's binary format. Also, integer grids are stored in a compressed format, which cannot be maintained in the export file.