How to access to Oracle 12c schema from Oracle 11g instance

Question

We have two cloned schemas (from 11g to 12c). One was created in 2016 and another was created in 2019. Can anyone please advise on how to connect to cloned schema (12c) from 11g client?

I am able to connect to the schema cloned (12c) in 2016 from 11g client. However, I am unable to connect to the schema which was cloned (12c) in 2019.

Anyone's inputs on priority are highly appreciated.

Answer 1

This is how I understood the question: in order to connect to any database, we use a connect string, eg

connect scott/tiger@orcl

ORCL represents the database. Usually, it is an alias we put into TNSNAMES.ORA file and looks like this:

ORCL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = db_server_2)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = ORA11G)
    )
  )

In order to connect to a new database, you'll have to edit that file and add another alias, to that newly created database. It will probably have another host name and service name. Which ones are they, I don't know. If you know it, fine; if not, ask your DBA.

Suppose it'll look like this:

ORCL12C_2019 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = db_server_12C)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = ORA12C_2019)
    )
  )

Then you'd connect to it as

connect scott/tiger@ORCL12C_2019