Follow this procedure to prepare, create, and run Oracle Database instances on Leaf Nodes.

1. Prepare the nodes as follows:
   1. Connect Leaf Nodes to storage, if not already connected.
      Running database instances on Leaf Nodes requires that they have direct storage access.
   2. Install Oracle Database home on all required nodes, and at least one Hub Node. See the topic Using Oracle Universal Installer to Install Oracle RAC for the procedure to install Oracle RAC.
      To run a database instance on a Leaf Node, you must install a database home, similar to any other node.
   3. Extend public network to Leaf Nodes:

      srvctl modify network -netnum 1 -extendtoleaf YES
      srvctl add vip -node leaf_node -netnum 1 -address
      leaf_node_vip
      srvctl start vip -node leaf_node
      srvctl modify listener -extendtoleaf YES

      If you use Grid Naming Service (GNS) and Dynamic Host Configuration Protocol (DHCP) for your cluster, then run the following, instead of the above command:

      srvctl modify network -netnum 1 -extendtoleaf YES
      srvctl start nodeapps
      

   4. Check if the Leaf Node is an Oracle RAC Reader Node:

      crsctl get cluster type

2. Create a policy-managed Oracle RAC database using Oracle Database Configuration Assistant (DBCA).
   Oracle RAC Reader Nodes and Massive Parallel Query Oracle RAC require a policy-managed database. You cannot extend admin-managed databases to Leaf Nodes.
   1. For Massive Parallel Query RAC, create new server pools along with the database. Ensure that you create one Parallel Query server pool.
   2. For Oracle RAC Reader Nodes, create databases on Hub Nodes. The addition of database instances on Leaf nodes is dynamic and is managed from the command line.
3. For Oracle RAC Reader Nodes, add a Reader Farm server pool RF1POOL to the system using the add service command.

   srvctl add srvpool -serverpool RF1POOL -category LEAF
   srvctl add service -database rfdb -service RFWL -rfpool RF1POOL
   srvctl start service -database rfdb -service RFWL
   srvctl status service -d rfdb

4. Connect to the database:

   sqlplus 
   CONNECT system/mypassword@mydbserver.mydomain.com

   If you use a Leaf node for massive Parallel Query Oracle RAC, then you cannot connect directly to the Leaf node instance.