gd@aprm (Gary Dunn) (12/18/90)
Text:
I've been thinking about how to implement a distributed database with
sites located in Hawaii, Alaska, Japan, and Korea. I see where ORACLE
(and others) support SQL over tcp/ip networks. Is there any chance that
this could be done using the DDN to carry the query/response traffic?
Hardware is not known, but assume the following for discussion:
server: ISA or EISA PC running SCO UNIX 386 w/tcpip
client: 286 PC running MS-DOS version of DBMS vendor's SQL access
software, FTP's PC/TCP
A CISCO box (X.25 router/gateway) would be used at each end. The one in
Hawaii is up and running (that's how you got this) and the other's have
been purchased.
The alternative would be async modems, but service to the remote locations
is pretty awful.
I've spoken to ORACLE, SCO, and FTP about this, and while they all agree
it's an interesting idea, none could comment on it's technical
viability.
So what do you think? Would it work? Is it a dog? Is there a better
way?
Thanks in advance...
Gary Dunn, USARPAC DCSRM IMO |
Ft. Shafter LAN: aprm%gd _ _ |
DDN: aprm%gd@shafter-emh2.army.mil /.\ /.\|
Work phone: (808) 438-2716 \_/|\_/
FAX: (808) 438-8954 |
/
Real programmers don't comment their code. If it was
hard to write, it should be hard to understand, and
even harder to modify.
--- End of Message -----------jbvb@FTP.COM (James B. Van Bokkelen) (12/21/90)
I've been thinking about how to implement a distributed database with
sites located in Hawaii, Alaska, Japan, and Korea. I see where ORACLE
(and others) support SQL over tcp/ip networks. Is there any chance that
this could be done using the DDN to carry the query/response traffic?
There are two main issues: throughput required, and response time. Things
one would need to know in order to evaluate it are: How many clients will
be talking to one server? What's the transaction rate you want to provide
to a single client? How many data exchanges (and thus round-trip-times)
does a single transaction require? For what fraction of a transaction will
the database need to be locked against other clients? What are the minimum,
maximum and average round-trip times you expect the net to provide? The
major pitfall would appear to be long round-trip-times leaving the files
locked for much longer per transaction than you might initially guess, and
this could greatly reduce the overall transaction rate.
James B. VanBokkelen 26 Princess St., Wakefield, MA 01880
FTP Software Inc. voice: (617) 246-0900 fax: (617) 246-0901wrl@wdl51.wdl.fac.com (Bill Lewandowski) (12/21/90)
I don't see why it would not work as long as all the SQL servers were on the DDN. Data seems to move between DDN sites fine. Its when you have DDN-Internet that the mailbridges (as their called) seem to screw things up. Just remember that their are packet charges on the DDN and you need to figure out how much data you are going to be generating. DCA might not appreciate it if you swamp there network. I'm not sure but I still think most oveseas circuits between switchs are 9.6 (I could be wrong). Bill =========================================================== -- Bill Lewandowski LORAL Western Development Labs (408) 473-4362 Internet: wrl@wdl1.wdl.loral.com FAX: (408) 473-7926 UUCP: wdl1!wrl