Re: Definitions Help

As a further refinement, Oracle defines: ORACLE_SID - This parameter specifies the name of the Oracle7 RDBMS on the host machine. The value of this parameter is system identifier (SID) for the database.

Oracle defines "database" as the physical collection of tables, indexes, etc. (stored in tablespaces which in turn are stored in operating system files) with 1 or more instances (Oracle Server software) running against a single database.

A schema is the logical collection of tables, index etc of interest to DBAs and developers. A schema can cross tablespace boundaries and even database boundaries.

An instance serves one database (handling queries, inserts, updates etc), but can link to other instances remotely.

• Dan Clamage (Pete I chuckled when I saw your ASCII guy below) Pete Desnoyers <peted_at_infi.net> wrote in article <342A7688.794B_at_infi.net>...
  > It's not stupid. In fact, these questions are the source of much
  > confusion. I'll do the best I can to explain it in simple terms and I'm
  > sure there are others who can do better, but I'll try to help.
  >
  >
  > David Parry wrote:
  > >
  > > What is the definition and difference between:
  > >
  > > 1)Database - A collection of datbase objects such as tables, indexes
  and views. You can have multiple databases per instance.
  > > 2)Instance - An Oracle process with it's own SGA. You can have
  > multiple instances running at the same time. However,
  > if you want multiple instances accessing the same
  > database, you must use parallel server.
  > > 3)SID - A User defined name for an instance.
  >
  > Again, this is simple, butI hope it helps.
  >
  > Pete
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  >