sparse file

A file with at least one empty block. (NetWare wont write any block that is completely empty.) Databases often create sparse files.

For example, suppose the disk allocation block size for volume Vol1 is 4 KB. Also suppose that a database opens a new file, seeks out the 1,048,576th byte, writes five bytes, and closes the file. An inefficient operating system would save the entire file to disk.The file would be comprised of 256 zero-filled disk allocation blocks (the first 1 MB) and one more disk allocation block with five bytes of data and 4,091 zeros. This method would waste 1 MB of disk space. However, NetWare writes only the last block to disk, saving time and disk space.