Re: AS/400 Transparent gateway question.

jfk_at_sigsys.com writes:

>--How does ORACLE define the files on the AS/400?

Oracle doesn't define the files on the AS/400. The Transparent Gateway for DB2/400 allows Oracle databases and clients to access the data defined on the AS/400. All data definitions are done on the AS/400 with AS/400 tools.

>--Can we create (and possibly populate) the AS/400 files ahead of time, or are they created only after ORACLE
> is started/configured?

You can create the files at any time. Data creation is unrelated to the Oracle process. Simply use the existing AS/400 tools to manage your data.

>--Can users UPDATE files on the AS/400 side?(thus removing ORACLE's integrity constraints)

Users are free to update files on the AS/400.

>
>Any assistance would be appreciated.
>
>Thanks in advance - JFK

Basically, the Oracle Transparent Gateways provide access to existing data systems. The only definition on the Oracle side is a database link which tells Oracle about the remote gateway. Once this definition is done you can access the data.

Assume that you have a table called db2400emp on the AS/400 and that you've called your Oracle Transparent Gateway for DB2/400 tg4db2400. Your tnsnames.ora file (part of SQL*Net's configuration) would contain a network definition pointing to the gateway. This definition could be called tg4db2400 as well. A sample tnsnames.ora file:

tg4db2400 =

	(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=devas400)(PORT=1523))
	(CONNECT_DATA=(SID=TG4DB2400)))

Once this network definition is in place you can sign onto Oracle and create a database link:

SQL> create database link tg4db2400 using tg4db2400;

That's the end of the Oracle definition to access your AS/400 data.

At this point a client could enter the following SQL:

SQL> select * from db2400emp_at_tg4db2400;

I would recommend that you create a synonym:

SQL> create synonym db2400emp for db2400emp_at_tg4db2400;

Now:

SQL> select * from db2400emp;

The Transparent Gateway for DB2/400 also provides two-phase commit between Oracle databases and DB2/400 databases.

Users are still free to update the AS/400 data. The Transparent Gateway for DB2/400 appears as another client process updating the AS/400 data, so normal locking and concurrency control issues will still apply.

Dave Dargo (ddargo_at_us.oracle.com) Received on Sat Jun 29 1996 - 00:00:00 CEST