clusters and HA?

[Mike]

We're starting a project at work moving VSAM to RDBMS. The choice
is between DB2 and Oracle. It seems like the Oracle RAC is a better
cluster choice with it's share everything rather than the DB2
share nothing. Please post some opinions on this and/or other
points of difference/intereste between the two DBMS.

Mike

[Blair Adamache]

If you measure the number of machines in the cluster as a measure of
scalability (i.e. how large a database can be supported, how complex the
queries can be), my limited and biased experience shows DB2 to be ahead
of Oracle on UNIX, Linux and Windows.

When DB2 Stinger ships (later this year), which has a feature called
Client Reroute, Oracle and DB2 will be more or less equal for
transparent application failover (Oracle's shared disk approach has
strengths and weaknesses compared to the shared nothing approach which
has been adopted by DB2 UNIX/Linux/Windows, Informix XPS, Teradata and
SQL Server).

BTW, in this newsgroup, your question is about to cause a free for all
similar to throwing a raw steak into a Lions' den.

Mike wrote:

We're starting a project at work moving VSAM to RDBMS. The choice
is between DB2 and Oracle. It seems like the Oracle RAC is a better
cluster choice with it's share everything rather than the DB2
share nothing. Please post some opinions on this and/or other
points of difference/intereste between the two DBMS.

Mike

[Walter Schneider]

Hello,

the term VSAM indicates to me, that you're currently on a OS/390 or z/OS
platform. This platform offers the Parallel Sysplex cluster technology,
which can be exploited by DB2 for z/OS to build up full data sharing RDBMS
clusters (in difference to the shared nothing architecture of other members
of the DB2 family) which are comparable to ORACLE's RAC technology (with the
slight difference, that this DB2 data sharing groups are already available
and in use since more than 6 years...)

To avoid the start of any new ORACLE-DB2 discussion, here is my straight
opinion about the difference between them two RDBMS's in advance:

For me, ORACLE and DB2 differ through their common SQL-language, just like
Germans and Austrians do through their common German language.

Regards - Walter SCHNEIDER.
"Mike" <mi***@mikee.ath.cx> schrieb im Newsbeitrag
news:10*************@corp.supernews.com...

We're starting a project at work moving VSAM to RDBMS. The choice
is between DB2 and Oracle. It seems like the Oracle RAC is a better
cluster choice with it's share everything rather than the DB2
share nothing. Please post some opinions on this and/or other
points of difference/intereste between the two DBMS.

Mike

[hrishy]

Hi Blair

Can you say more about client reroute on stinger..

regards
Hrishy
Blair Adamache <ba*******@2muchspam.yahoo.com> wrote in message news:<ca**********@hanover.torolab.ibm.com>...

If you measure the number of machines in the cluster as a measure of
scalability (i.e. how large a database can be supported, how complex the
queries can be), my limited and biased experience shows DB2 to be ahead
of Oracle on UNIX, Linux and Windows.

When DB2 Stinger ships (later this year), which has a feature called
Client Reroute, Oracle and DB2 will be more or less equal for
transparent application failover (Oracle's shared disk approach has
strengths and weaknesses compared to the shared nothing approach which
has been adopted by DB2 UNIX/Linux/Windows, Informix XPS, Teradata and
SQL Server).

BTW, in this newsgroup, your question is about to cause a free for all
similar to throwing a raw steak into a Lions' den.

Mike wrote:

We're starting a project at work moving VSAM to RDBMS. The choice
is between DB2 and Oracle. It seems like the Oracle RAC is a better
cluster choice with it's share everything rather than the DB2
share nothing. Please post some opinions on this and/or other
points of difference/intereste between the two DBMS.

Mike

[Blair Adamache]

You're probably best to download the beta (or at least the beta
documentation): http://www-306.ibm.com/software/data/db2/stinger/

Before Client Reroute, when a system crashed, its IP address would be
assumed by the standy machine (or mutual takeover machine), the app
would lose the connection and have to reconnect.

With Client Reroute, the connection is transferred with the IP address,
so if all goes according to plan, the application need not reconnect.

hrishy wrote:

Hi Blair

Can you say more about client reroute on stinger..

regards
Hrishy
Blair Adamache <ba*******@2muchspam.yahoo.com> wrote in message news:<ca**********@hanover.torolab.ibm.com>...

If you measure the number of machines in the cluster as a measure of
scalability (i.e. how large a database can be supported, how complex the
queries can be), my limited and biased experience shows DB2 to be ahead
of Oracle on UNIX, Linux and Windows.

When DB2 Stinger ships (later this year), which has a feature called
Client Reroute, Oracle and DB2 will be more or less equal for
transparent application failover (Oracle's shared disk approach has
strengths and weaknesses compared to the shared nothing approach which
has been adopted by DB2 UNIX/Linux/Windows, Informix XPS, Teradata and
SQL Server).

BTW, in this newsgroup, your question is about to cause a free for all
similar to throwing a raw steak into a Lions' den.

Mike wrote:

We're starting a project at work moving VSAM to RDBMS. The choice
is between DB2 and Oracle. It seems like the Oracle RAC is a better
cluster choice with it's share everything rather than the DB2
share nothing. Please post some opinions on this and/or other
points of difference/intereste between the two DBMS.

Mike

[Erik Hendrix]

Hey Blair,

What would happen with any open transactions? Since the app. does not need
to reconnect, I assume that app never knew that the database crashed then
and moved to another server.
But any open UOW will be rolled back by the database. So what happens there?

Thanks.

"Blair Adamache" <ba*******@2muchspam.yahoo.com> wrote in message
news:ca**********@hanover.torolab.ibm.com...

You're probably best to download the beta (or at least the beta
documentation): http://www-306.ibm.com/software/data/db2/stinger/

Before Client Reroute, when a system crashed, its IP address would be
assumed by the standy machine (or mutual takeover machine), the app
would lose the connection and have to reconnect.

With Client Reroute, the connection is transferred with the IP address,
so if all goes according to plan, the application need not reconnect.

hrishy wrote:

Hi Blair

Can you say more about client reroute on stinger..

regards
Hrishy
Blair Adamache <ba*******@2muchspam.yahoo.com> wrote in message news:<ca**********@hanover.torolab.ibm.com>...

If you measure the number of machines in the cluster as a measure of
scalability (i.e. how large a database can be supported, how complex the
queries can be), my limited and biased experience shows DB2 to be ahead
of Oracle on UNIX, Linux and Windows.

When DB2 Stinger ships (later this year), which has a feature called
Client Reroute, Oracle and DB2 will be more or less equal for
transparent application failover (Oracle's shared disk approach has
strengths and weaknesses compared to the shared nothing approach which
has been adopted by DB2 UNIX/Linux/Windows, Informix XPS, Teradata and
SQL Server).

BTW, in this newsgroup, your question is about to cause a free for all
similar to throwing a raw steak into a Lions' den.

Mike wrote:
We're starting a project at work moving VSAM to RDBMS. The choice
is between DB2 and Oracle. It seems like the Oracle RAC is a better
cluster choice with it's share everything rather than the DB2
share nothing. Please post some opinions on this and/or other
points of difference/intereste between the two DBMS.

Mike

[Blair Adamache]

The database will work with the available logs and replication records to commit
every transaction that can be committed, rollback every transaction that should
be rolled back, and, worst case, mark as "in-doubt" any transaction which will
need a DBA's help to be figured out (nothing will be marked in-doubt in almost
every circumstance). As in any crash situation, data integrity comes first.

Erik Hendrix wrote:

Hey Blair,

What would happen with any open transactions? Since the app. does not need
to reconnect, I assume that app never knew that the database crashed then
and moved to another server.
But any open UOW will be rolled back by the database. So what happens there?

Thanks.

"Blair Adamache" <ba*******@2muchspam.yahoo.com> wrote in message
news:ca**********@hanover.torolab.ibm.com...

You're probably best to download the beta (or at least the beta
documentation): http://www-306.ibm.com/software/data/db2/stinger/

Before Client Reroute, when a system crashed, its IP address would be
assumed by the standy machine (or mutual takeover machine), the app
would lose the connection and have to reconnect.

With Client Reroute, the connection is transferred with the IP address,
so if all goes according to plan, the application need not reconnect.

hrishy wrote:

Hi Blair

Can you say more about client reroute on stinger..

regards
Hrishy
Blair Adamache <ba*******@2muchspam.yahoo.com> wrote in message news:<ca**********@hanover.torolab.ibm.com>...
>If you measure the number of machines in the cluster as a measure of
>scalability (i.e. how large a database can be supported, how complex the
>queries can be), my limited and biased experience shows DB2 to be ahead
>of Oracle on UNIX, Linux and Windows.
>
>When DB2 Stinger ships (later this year), which has a feature called
>Client Reroute, Oracle and DB2 will be more or less equal for
>transparent application failover (Oracle's shared disk approach has
>strengths and weaknesses compared to the shared nothing approach which
>has been adopted by DB2 UNIX/Linux/Windows, Informix XPS, Teradata and
>SQL Server).
>
>BTW, in this newsgroup, your question is about to cause a free for all
>similar to throwing a raw steak into a Lions' den.
>
>Mike wrote:
>
>
>>We're starting a project at work moving VSAM to RDBMS. The choice
>>is between DB2 and Oracle. It seems like the Oracle RAC is a better
>>cluster choice with it's share everything rather than the DB2
>>share nothing. Please post some opinions on this and/or other
>>points of difference/intereste between the two DBMS.
>>
>>Mike