"Unlike a normal Oracle database, where there’s a single instance for the entire database, Oracle Real Application Clusters allows multiple instances to access a single database, and an Oracle RAC database can have a maximum of 100 instances."
via Check out this quote from Oracle Database 12c Release 2 Oracle Real Application Clusters Handbook: Concepts, Administration, Tuning & Troubleshooting - https://learning.oreilly.com/library/view/oracle-database-12c/9780071830478/ch3.xhtml
Oracle Real Application Clustersでは最大100のInstanceがDatabaseに接続する。
