unix file structure (or lack of same)

[Conor P. Cahill]

In article <125379 at linus.mitre.org> duncant at mbunix.mitre.org (Thomson) writes:
>I understand that, on unix, the file system is designed so that a file always
>looks like a sequence of bytes, with no record structure at all.

No *system imposed* record structure.

>If so, how does one implement an efficient database manager on unix in
>a standard, portable, way?  To be efficient, a database manager needs to

By having an application imposed record structure.

>have random access into files on a record-oriented basis.  It seems to me
>that fseek() wouldn't do the job.  

Most UNIX DBMSs will use read/write/lseek as opposed to the stdio functions
to ensure that the stdio buffering does not get in the way.

>provide a record-oriented view of files, then any database implementation 
>would have to go below unix, and access the mass storage devices directly.
>Is this right?

Nope.  It would only have to impose its own record structure on the file.


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