Oracle RAC can you have a cluster that contains one node

oracle

Have oracle RAC production system. Two nodes in the primary, two nodes in the secondary. Getting a test system.Can we have two nodes in the primary and one in the secondary? Or to put it another way – can you have a one node cluster in standard oracle RAC?

Best Answer

From the documentation:

Oracle RAC One Node is a new option available with Oracle Database 11g Release 2. Oracle RAC One Node is a single instance of an Oracle RAC enabled database running on one node in a cluster. This option adds to the flexibility that Oracle offers for database consolidation while reducing management overhead by providing a standard deployment for Oracle Databases in the enterprise.

This is a means to have a multi-node RAC, one which one database can only run on one node at a time, so it allows you to (more cheaply) use RAC for active-passive clustering, which saves on having both RAC and another clustering product such as VCS. Or are you asking if it is possible to have a RAC system entirely on one physical host, running Clusterware, ASM, etc and a database? Yep, that is possible too, the standard installer can do this for you.