On Friday 14 July 2006 02:48, Doug Cutting wrote: > drwho wrote: > > Also, would the lack of overwrite / random-write ops mean that the > > filesystem is less suitable for apps like online word-processor or even > > online spreadsheet / database ? > > Yes, such applications are probably not appropriate for direct > implementation on top of DFS. It would work, but it would not be the > best utilization of resources. Google uses BigTable, layered on top of > GFS, to store small items that may be independently updated. Hadoop may > someday incorporate something like BigTable. Mike Cafarella has > discussed this a bit on the hadoop-dev list:
In a past life I worked on a VFS and IFS implementation for Linux and Windows. While testing with various applications we found that applications rarely do overwrite and random-writes. Actually, since we weren't testing databases, none of the applications we tested with did overwrite and random-writes. Usually when an application saves something it writes it to a temporary file and then does a rename to overwrite. This prevents problems if a crash occurs during the save operation. ben
