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Lee,
The following in Vax/Document format are SOME major weaknesses of Oracle.
I hope it helps.
Best Regards, Jeffrey
<chead>(The Weak Points in Oracle's Offerings Are:)
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<emphasis>(Weak Dictionary)
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Data Validation and attributes need to be defined multiple
times; once for each application. In Vax/Rally, you define
them once in CDDplus. This saves a lot of time in development
and maintenance and provides a much easier way to ensure
data integrity.
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<emphasis>(Cluster Support)
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Oracle does not work well on a cluster because they do not
use Digital's Distributed Lock Manager (DLM). Rally on the other hand
layered tightly on Rdb/VMS Digital's proprietary RDBMS which has the most
robust integration with the operating system VMS. As such full automatic
cluster recovery is possible with Rdb/VMS and not Oracle.
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<emphasis>(Symmetrical Multiprocessor Support (SMP))
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Oracle does not take advantage of SMP on Vaxes. In fact it takes a
long time before Oracle can made to run on VMS version 5.
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<emphasis>(4GL Not Full Function)
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Oracle's 4GL (SQL*Forms, SQL*Plus and SQL*Reportwriter)
cannot develop complex systems without 3GL support. In
fact, their financials are written in Cobol. Rally is
a full function 4GL with capability to perform fairly complex
validation without branching to 3GL. However in situation where there is
need to interface with existing 3GL routines, Rally does provide 2 methods
of external link to the 3GL world.
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<emphasis>(Can Only Access Own DB)
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Oracle can only access the Oracle database. It does not
support RMS or Rdb. Rally has access to Rdb, RMS, DBMS as well
as FIX files. Through another piece of software called VIDA,
IBM databases such as VSAM and DB2 can be made available.
With Rally you do not have to throw away your
existing applications. With Oracle, you have to convert.
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<emphasis>(Security)
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Oracle has to define security for each user. Rdb can define
security by user classes. Oracle is much more time
consuming to define and manage security and much more prone
to error.
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<emphasis>(Distribute Update)
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Oracle can update only one remote database at a time. Rdb
can update multiple distributed databases at the same time.
Oracle is not a true distributed alternative given this
limitation.
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<emphasis>(Referential Integrity and Record Locking)
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Oracle has to define referential integrity constraints once
for each form that references the item. Rdb defines
referential integrity constraints once at the database
level. This is much more efficient and less error prone.
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Referential Integrity and Record Locking comes FREE with the standard
Rdb licence.
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<emphasis>(One Big Database)
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Oracle can have only one database per machine. (They can
work around this by installing it more than once on the same
machine but this is messy). Rdb can have many databases on
the same machine. Smaller databases are much easier to
manage than one large database that holds everything.
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<emphasis>(Periodic Database Maintenance)
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Oracle requires that the database be shut down for periodic database
reorganization and perform database backups. Rdb/VMS operates round the
clock with no neccesity to shutdown down for reorganization. The reason being
as follows:
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- space allocations and deletions for record insertions and deletions
respectively are dynamically and automatically re-organized.
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- Backup can be performed ONLINE with users accessing the database.
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- Backup can be done concurrently with multiple tape drives.
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<emphasis>(SQL Compliant and 3GL precompilers)
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Oracle SQL is not fully compliant to ANSI standard.
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Oracle 3GL precompilers are not code optimised.
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<emphasis>(Summary)
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Rdb/VMS is a full function full feature RDBMS most optimised on Vaxes.
As today, audited benchmarks revealed that Rdb/VMS is the fastest
RDBMS on the Vax.
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| ==> 1. Monitoring - does Oracle offer anything similiar to RMU?
Oracle V5 has ODS and V6 has SQL*dba. Both are just fair as monitors.
RMU has advantages because you can focus the displays on certain
types of I/O, locks, etc. RMU also allows you to write a binary
file for playback later. This is an excellent tool for capturing
those stats while you're sleeping.
==> 2. Multifile Databases - how big of a database does Oracle support?
Can an Oracle DB be broken up over many disks?
As big as your disk farm as far as I know. You can spread the Oracle
tables and/or indexes all over the place. They do not have horizontal
partitioning or hash indexes so we have an advantage there.
==> 3. Referential Integrity using constraints - Does Oracle provide this?
No. V6 has syntax for this so you can start putting them in but
they are not inforced until some future version. Let's see .. what
is that phrase ... not in your lifetime !!
==> Are these arguable points or is it like comparing apples to oranges?
It depends if that feature is important to your customer. Some
customers I've worked with wouldn't touch constraints while other
wouldn't be without them.
==> Keep pounding Oracle's lack of VAXcluster support for V6 IF your
customer believes VAXclusters are his best growth and investment
protection option. On the other hand, if your customer has a nasty
taste in his mouth from a small LAVC with slow disks, walk quietly.
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