| > My customer got a evaluation report that says IngresStar way of
> doing distributed database is more superior.
Superior to what ? There are not many implementations of distributed db's
around now.
One flaw I find in the Ingres/Star architecture is that it really is a separate
product layered on top of Ingres itself. In other words, the process to follow
is to define your individual Ingres 6.3 databases on your various machines,
then define your 'virtual' Ingres/Star database that will include part or all
of the various local databases.
Your application then talks to an Ingres/Star server which will break your
query into individual requests and ship them to the individual db servers.
This is different from an 'inherently' distributed database, where there should
not be such a strong distinction between the global distributed database and
its various local pieces. Among other things (someone correct me if I am
wrong), Ingres/Star does not allow you to transparently partition a table over
multiple local databases and does not handle multiple copies of the same
information (to cope with local or communication failures) ...
/albert
|
| IngresStar currently provides <I'm sorry to say> the most extensive
heterogeneous database environment on the market today. They have
transparent read/write gateways to Rdb, RMS, DB2, SQL/DS, VSAM, and
IMS (the IMS gateway is read-only). They can support joins across
heterogeneous database systems. But, IngresStar is not a truly
distributed database, ie, it do not support vertical or horizontal
partitioning of tables across databases. In other words, IngresStar
is a layered product that coordinates retrieval of data from a number
of heterogeneous data sources. Extensive defintions are required in
the IngresStar catalog in order to provide directions to all the
systems. IngresStar supports a subset of the Ingres SQL sub-language,
the lowest common demoninator SQL subset (only those commands which are
supported in INGRES, Rdb, DB2, _and_ SQL/DS), so it isn't really a
truly transparent gateway product. But it's definitely our toughest
competition.
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