interview question

[hrishy]

Hi

I was asked this in a interview could anybody expalin whats happening here

TNS Ping Utility for Solaris: Version 8.1.7.0.0 - Production on 24-APR-2001 12:24:21

(c) Copyright 1997 Oracle Corporation. All rights reserved.

Attempting to contact
(ADDRESS=(PROTOCOL=TCP)(HOST=10.1.2.3)(PORT=1521))
OK (1 msec)

testuser@test-01 /data/testuser
337 $ sqlplus devuser_owner/dev@TEST01

SQL*Plus: Release 8.1.7.0.0 - Production on Tue Apr 24 12:24:38 2001

(c) Copyright 2000 Oracle Corporation. All rights reserved.

ERROR:
ORA-12545: Connect failed because target host or object does not
exist

regards
Hrishy

[tamilselvan]

In the tnsnames.ora file you must have a valid entry for the host name or IP address.

Tamil

[hrishy]

Hi

How come tnsping works then ?

regards
Hrishy

[pando]

tnsping pings the listener not the database, it's listener which says: hey I am serving this instance and I am ready for it!

[hrishy]

Hi

But the listener will be listening on a particular host (or a IP ) right ?

regards
Hrishy

[Mr.Hanky]

HUH!?

Where the hell is the question, I'm only on my 4th matini so I can't be missing this one.

[tamilselvan]

==============
HUH!?

Where the hell is the question, I'm only on my 4th matini so I can't be missing this one.
__________________
Self-Appointed Political Correctness Advisor.

=====================

Is it "martini" or "matini" ?

Tamil

[marist89]

Originally posted by tamilselvan
Is it "martini" or "matini" ?

matini = martini mixed with Graves instead.

[abhaysk]

Originally posted by hrishy
Hi

How come tnsping works then ?

regards
Hrishy

are you sure tnsping was with test01 and not test-01?

[jmodic]

Originally posted by hrishy
But the listener will be listening on a particular host (or a IP ) right ?

Pando allready gave you the aanswer. Your instructed tnsping utility only to check if the listener is alive.

(ADDRESS=(PROTOCOL=TCP)(HOST=10.1.2.3)(PORT=1521)) is merely TNS address of the listener, it doesn't tell anything about which database you are interested in. That listener could be listening on that host/port for N databases, where N could be 0, 1 ,2 or zillion of databases. You simply asked: "Hey, tnsping, tell me if the lsitener on IP 10.1.2.3, which listenes on port 1521, is alive?". And you've got positive answer.

But if you would have asked: "Hey, tnsping, tell me if the lsitener on IP 10.1.2.3, which listenes on port 1521, is alive and listening for the incoming connections for the database TEST01?", the tnsping would have given you exactly the same answer as your sqlplus have: ORA-12545: Connect failed because target host or object does not exist.