This variable is used to define the compression factor that is applied to indexed files (if the indexed file system supports compression; Vision does). COMPRESS_FACTOR is applied when a file is created with the WITH COMPRESSION phrase in the ASSIGN clause of the file's SELECT and the COMPRESSION CONTROL VALUE phrase is either omitted or specifies a value of 1. If the COMPRESS CONTROL VALUE phrase specifies a value other than one, that value is used and the value of COMPRESS_FACTOR is ignored.

COMPRESS_FACTOR can be set to any value within the range zero to 100. Zero specifies no compression. Values from 2-100 are treated as a percentage that specifies how much of the space saved by file compression is removed from the compressed records. A value of 1, the default, is a special case that causes the standard default compression factor of 70 to be applied. Note that a file's compression factor is set when the file is created and cannot later be changed except by recreating the file or rebuilding the file with vutil. For more information about Vision record compression, see Compression. in the ACUCOBOL-GT User's Guide.