Setup wizard tries to detect existing Oracle homes to ease the installation, however there are some limits:
- On 64-bit Windows, it searches installation for the same 32-/64-bit binaries as what the Dbvisit Replicate executables are, because ORACLE_HOME has to be set to use same binaries type. However, you can set TNS_ADMIN to point to the different binaries type, as this is used for text-file network configuration only.
- On Linux and Solaris, oratab is parsed to detect Oracle homes. This usually means it won't find Oracle client installations etc., when no database is configured.
- TNS_ADMIN checks detected ORACLE_HOMEs and checks for existence of sqlnet.ora/tnsnames.ora in network/admin subdirectory or directly in the ORACLE_HOME.
- As with all checks in setup wizard, the detection works only on the local machine. Check that the settings are valid for other nodes and servers as well.