The difference between sequential data access and random data access files in oracle
There is no difference in the files, only in the way they
are accessed. Sequential files are accessed just like they sound, sequentially,
which means that if you want to read something that starts at byte number
40,000, you have to read and ignore the first 39,999 bytes. Random-access
files, however, allow you to go directly to the exact location you want.
LONG and LONG RAW data types
= sequential data access