BLOB is an acronym for “Binary Large OBject”. It is the database term for any (usually large) amount of data that is not a fixed size. In SMS, common BLOB types are
In Paradox, fixed size data is stored in the *.DB file. This file is orderly, fast, indexed, and can be read and written very quickly. In contract, BLOB data in Paradox is stored in the *.MB file.
If you put a BLOB record in the database, the .DB file will have an offset (pointer) saying where in the .MB file the BLOB is stored. It also has a size indicator, to say how many bytes the BLOB is.
Accessing a BLOB file involves finding the record in the .DB file, getting the pointer to the BLOB in the .MB file, reading down the .MB file until you come to the BLOB, and reading the number of bytes specified.
A BLOB Corruption occurs when the pointer into the .MB file does not start or end with a BLOB, and usually means that at least some data may be corrupted or lost.
See Also: sms_error_-_index_out_of_date.
UPDATE "Order Details Database" SET ModifierXML = '' WHERE OrderDetailID > 0