20C oracle database tnsnames.ora location_oracle database file location

一般会在$ORACLE_HOME/network/admin

但是20c上，默认在其他位置。

查询方法：lsnrctl status 

看到参数Listener Parameter File中XXX/network/admin/下可以修改tnsnames.ora

/sysdb/homes/OraDB20Home1/network/admin/tnsnames.ora

Both directory homes and product are at the same layer 

As we know product's next directory layer is dbhome_1

这个路径变化是因为ROOH 被启动了：

If you are going to test RDBMS MAIN (20.1) label on shiphome env, it might be helpful to know:

ROOH (Read-Only Oracle Homes) feature is introduced in 18c as an alternative to traditional Read-Write Oracle Home. ROOH is disabled in 18c and 19c unless manually turning ON with :

$ORACLE_HOME/bin/roohctl -enable

But starting from 20.1 ( I tried with the latest RDBMS MAIN label) ROOH seems becoming default setting after install RDBMS binary, this change will impact most of our STORCH automation scripts of install/setup testing DB env because of Oracle Homes/Bases hierarchy change.  There are two solutions to this change:

1. modify our STORCH script to accommodate ROOH hierarchy 

2. For reuse our existing STORCH script to install/setup DB , run $ORACLE_HOME/bin/roohctl -disable after install RDBMS binary and before create DB with DBCA. 

To know more about ROOH, please refer to: 

https://docs.oracle.com/en/database/oracle/oracle-database/18/ladbi/configuring-read-only-oracle-homes.html#GUID-906DA159-AC83-4ACC-A8A6-5B4A39EB72E1