On 29 Jun 2016, at 5:45pm, Drago, William @ CSG - NARDA-MITEQ <william.dr...@l-3com.com> wrote:
> Aren't there things like that already built in to the hard disk controllers > (CRC, Reed Solomon, etc.)? Yes. But they operate at the level they understand. For instance ... A change is made in a field which involves changing just one page of data. In terms of the SQLite file format this would mean that a table page is overwritten -- a one disk sector change. If SQLite checksums existed then this would mean that the checksum, stored in the table pointer page, would also have to be updated. Which would mean that another disk sector has to be changed too. Now suppose there's a big in the storage medium driver which means it occasionally writes the correct data to the wrong sector on disk. Without checksums this fault would not be noticed: since the wrong sector on disk was updated the wrong checksum on disk would be updated too. The errors would match. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
