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"Sybrand Bakker" <gooiditweg_at_sybrandb.nospam.demon.nl> wrote in message
news:umvgsvourqne30skm5la8bmf13unj9kjum_at_4ax.com...
> Comments embedded
>
> On Sat, 29 Nov 2003 00:28:55 -0600, "Burt Peltier"
> <burttemp1ReMoVeThIs_at_bellsouth.net> wrote:
>
> >Just looking for some opinions (or please correct me if I am wrong) on
this
> >subject...
> >
> >Just my 1 opinion, but it seems most shops could just use the Hostname
> >Method for most databases and then have a 2nd fallback method (multiple
> >methods easily configured in sqlnet.ora in 1 line) of the simpler
> >Local(tnsnames) Method.
> >
> >The other option of Onames/LDAP seems like overkill for something as
simple
> >as looking up a database, especially in an Intranet network (most
shops?).
> >
>
> IIRC, as soon as you have multiple instances on one server, you can't
> use the hostname method. Hence I assume most shops can't use the
> hostname method at all.
Not true.
I can see posting comments on Onames which you seem knowledge-able about,
but you obviously know almost nothing about Hostname.
We have as many as 5 production instances (for the last 3 years I might add)
on 1 machine using Hostname by using a separate TCP/IP alias. The alias that
the GLOBAL_DBNAME points to in the listener.ora for each individual database
is the one that works for it.
>
> >1) The Local Method which uses a tnsnames.ora file has problems, but is a
> >well known method. It of course has the biggest disadvantage of
replication
> >at the file system level. Of course, depending on the size of the
company,
> >the replication could be simple or very complex and problematic.
>
> Usually no tnsnames.ora will be identical, because people want to have
> their 'own' databases only. Also name resolution using tnsnames.ora is
> definitely much slower than using onames. Basically, in many
> orgnisations tnsnames will be a PITA
>
>
I agree that tnsnames.ora can become a "mess" (multiple copies), if clients
can change where Oracle picks up the tnsnames.ora from (and there are
several ways to change this). That is why we consider it a fallback to
Hostname. Also, in our new organization, client's W2K ("locked") desktops
prevent them from easily changing this, although we have a process where a
client could easily add 1 entry to the top of the tnsnames.ora file. Being
at the top it will never override production entries below it in the
official tnsnames.ora (which is not edit-able by clients).
It seems the only people that want (or should be allowed) to have their
'own' databases are mainly developers/DBAs or support staff. This seems
required to do their job and they should be able to fix their own "multiple
copies mess". In our new organization, these people are "unlocked" and can
do anything on the desktop.
> >
> >2) The Hostname Method is by far the simplest to implement and maintain.
>
> Not true.
Statement #2 is of course true.
So, you are saying adding 1 line to the listener.ora and creating 1 TCP/IP
alias is not simple? Absolutely ZERO client *.ora files are required ... is
not simple?
>
> It
> >simply uses the existing DNS IP lookup method. It has the big advantage
of
> >ZERO client configuration and ZERO extra infrastructure (no Onames or
LDAP
> >server required and no file system replication required). It also appears
to
> >be quicker in every case (even when Hosntame is the LAST method to check
in
> >the sqlnet.ora config file specification - ok just 30 or 40 milliseconds,
> >but still quicker).
> >
> >Of course it has the big disadvantage of requiring use of all defaults
for
> >things like port number and use of a TCP network. There are a couple of
> >other limitations like you cannot use MTS or "failover - some NT/W2K
option
> >I think - not sure".
>
> Failover has NOTHING to do at all with a specific platform. You are
> confusing failsafe and failover.
> I wouldn't call not being capable to use MTS a 'limitation'. That is
> just a blatant understatement.
Ok. As I said "not sure" . You are probably correct ... I am confusing those
two... failsafe and failover.
I don't think I am understating anything ... I specifically listed all the
limitations ( I could think of and even 1 I was unsure of) and to catch
everything else ... I said anything that is not a default in tnsnames.ora
will not be possible with Hostname method.
So, what exactly is the understatement?
> >
> >But, aren't most people NOT using these non-default Net8 options and
> >therefore Hostname Method would work for most databases? With a simple
and
> >well understood fall-back method like Local(Tnsnames), would this be a
> >problem (used for some emergency or in case a non-default option becomes
> >necessary)?
> >
> >3) Onames (which will be replaced by LDAP storage) seems to have the
> >disadvantage of requiring the most extra infrastructure. I say "seems"
> >because I sorta remember someone saying it works best with an OID (Oracle
> >Internet Directory) LDAP storage . And, I am guessing not that many shops
> >have OID implemented for LDAP.
> >
> >Onames seemed cleaner and less problematic because at least it could be
> >stored in an existing database (as opposed to OID which I think should be
> >installed in a database dedicated to OID). Also, Onames could cache the
> >information in a local file if the Onames storage database was down,
which
> >again seems to make it also better than the LDAP replacement.
> >
>
> Onames *ALWAYS* caches the information, so Onames doesn't need to
> access the database to resolve a request. The cache file is
> synchronised at regular configurable intervals, and you can have
> delegated administration in various regions. Also, you don't need to
> maintain database links anymore.
>
> >
> >
> Seems like you don't have any working experience with Onames, and your
> background is a small company. If you have a larger organizations
> Onames and/or LDAP is the way to go.
>
Wrong. I work for a large corporation. I have worked with Onames on a 2nd
job and it has been 5 years. So, I forgot the detail about always cache'ing
to a local file.
I should "refresh" my Onames knowledge - oh wait. That's true, Oracle says
it is going away. So, why learn it?
As for LDAP... someone knowledge-able can please correct me on this if I am
wrong , but doesn't LDAP work better with OID (Oracle Internet Directory)?
Also, isn't the only other LDAP choice M$ 's implementation ?
I feel sorry for Onames clients ...
>
> --
> Sybrand Bakker, Senior Oracle DBA
Received on Sat Nov 29 2003 - 12:33:49 CST
