How to set PL/SQL Developer or TOAD to use a different oracle instance

Whether you have an oracle home setup or not:

* copy/setup PL/SQL Developer or TOAD to your system
* copy/setup Oracle Instantclient to your system
* add a System PATH Variable for Instantclient i.e.

[text]c:\users\oracle\instantclient

-if this is a 2nd instance add it after 1st instance:
c:\Oracle\Middleware\as_1\bin;c:\users\oracle\instantclient[/text]

* Run PL/SQL Developer or TOAD and configure to use the new instance and tns names

PLSQL: Tools > Preferences > set oracle_home and oracle_oci dll paths
TOAD: If set correctly, it will find the new instance

Note: recommended to use the same tnsnames.ora path for all applications