Re: SQL Existence Check

[Vernon Hamberg <vhamberg@xxxxxxxxx>]

OK, got ya. I'm just looking this up to learn a little more. Thanks for the
eye-opener.

So does the following definition, from Webopaedia, work here?

ISAM - Abbreviation for Indexed Sequential Access Method, a method for
managing how a computer accesses records and files stored on a hard disk.
While storing data sequentially, ISAM provides direct access to specific
records through an index. This combination results in quick data access
regardless of whether records are being accessed sequentially or randomly.

And the following?

"it is not uncommon for relational databases to be implemented using an
ISAM database library"

from http://www.ntlug.org/~cbbrowne/dbmsisam.html, Christopher Browne's Web
Pages?

This looks like physical layer implementation. What would have to happen
for a database to be relational at this level? Is not the 400 relational at
the user level?

At 05:36 PM 3/12/02 -0600, you wrote:
>From: Vernon Hamberg <vhamberg@attbi.com>
> > >IBM is not developing ISAM further on the AS400
> >
> > Uh, ISAM? I don't think that's what the DB is on AS/400 anyway. Or are they
> > lying to us when IBM calls it the relational database machine? A database
> > does not have to use SQL to be relational.
> >
>
>AS/400's DB is definitely ISAM. It is NOT relational. You can build
>SQL access on top of that. This is also done on the S/390 using VSAM
>as the underlying database engine.
>
>
>
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