Connecting to Oracle19C Server using Oracle11g client

Question

all

I'm trying to connect to an Oracle 19C database. I have installed two Oracle Clients (11g and 12c) because we need to support legacy programs. I can connect with no issue with any user using sqlplus through the 12c client. But if I use the 11g (11.2.0) client with any user. I always get:

ERROR:
ORA-01017: invalid username/password; logon denied

Both clients have exactly the same sqlnet.ora and tnsnames.ora files, so both clients point to the same database.

Any idea? Do I need to set some specific configuration in the 19c server? Or do I need to make some change in the 11g client? Is this even possible?

Thank you.

Answer 1

Have a look at Client / Server Interoperability Support Matrix for Different Oracle Versions (Doc ID 207303.1)

• #9 - 11.2.0.3 or 11.2.0.4 only. For Oracle Autonomous Transaction Processing and Oracle Autonomous Data Warehouse, there is additional limitation and 11.2.0.4 is the minimum supported client version.

Usually it is a bad idea to install more than one Oracle client (i.e. one each for 32-bit and 64-bit).

For some components, e.g. "Oracle OleDB Provider" it is even not possible to have more than just one version (again, one each for 32-bit and 64-bit) installed. This is a limitation of the old Windows COM architecture.

For other components it may work, however you need to set your %PATH% environment variable accordingly that it points to the correct folder where currently desired version is installed.

Answer 2

Add to sqlnet.ora

SQLNET.ALLOWED_LOGON_VERSION_CLIENT=11
SQLNET.ALLOWED_LOGON_VERSION_SERVER=11

Change the password in 11 client

Answer 3

I couldn't make a 11 client (ODP.Net + Instant Client 11.2) connect to a 19 DB, whatever changes I made to the sqlnet.ora file regarding security, etc. be it on the server or the client side. I always had a cryptic message about the impossibility to negociate protocols.

There was no problem when I installed Instant Client 19, except the fact that passwords are now case-sensitive. I can also use this new client with legacy databases running 11.2 software.

Answer 4

I have connected to oracle 19C Release 19.0.0.0.0 using ODAC 11.2.0 without any issue. But if you want to connected to oracle 19C higher release you need to have ODAC 11.0.3 or higher. Still looking for way to connect using ODAC 11.0.2 to later Oracle 19C release.