to demonstrate the scalability of their application. Most of the biggest OLTP benchmarks are on Oracle RAC. Oracle RAC 11g supports up to 100 nodes. For some applications, RAC may require careful application partitioning to enhance performance. An application that scales linearly on an SMP machine may scale linearly under RAC. However, if the application cannot scale linearly on SMP, it will not scale when ported to RAC. In short, the application scalability is based on how well the application scales in a single instance. Competitive context Shared-nothing and shared-everything architectures each have advantages over the other. DBMS vendors and industry analysts regularly debate the matter; for example, Microsoft touts a comparison of its SQL Server 2005 with Oracle 10g RAC. Oracle Corporation offered a Shared Nothing architecture RDBMS with the advent of the IBM SP and SP2 with the release of 7.x MPP editions, in which virtual shared drives (VSD) were used to create a Shared Everything implementation on a Shared Nothing architecture. Shared-Everything Shared-everything architectures share both data on disk and data in memory between nodes in the cluster. This is in contrast to "shared-nothing" architectures that share none of them. Some commercially available databases offer a "shared-everything" architecture. IBM Db2 for z/OS (the IBM mainframe operating-system) has provided a high-performance data-sharing option since the mid-1990s when IBM released its mainframe hardware and software-clustering infrastructure. In late 2009, IBM announced DB2 pureScale, a shared-disk clustering scheme for DB2 9.8 on AIX that mimics the parallel sysplex implementation behind Db2 data sharing on the mainframe. In February 2008, Sybase released its Adaptive Server Enterprise, Cluster Edition. It resembles Oracle RAC in its shared-everything design. Although technically not shared-everything, Sybase also provides a column-based relational database focused on analytic and datawarehouse applications called Sybase IQ that can be configured to run in a shared disk mode. Cloud Native Databases, such as Amazon Aurora and POLARDB of Alibaba Cloud, are implemented with "shared-everything" architecture on top of cloud-based distributed file system. Shared-nothing Shared-nothing architectures share neither the data on disk nor the data in memory between nodes in the cluster. This is in contrast to "shared-everything" architectures, which share both. Competitive products offering shared-nothing architectures include: MySQL Cluster (Oracle Corporation has owned MySQL since 2009) ScaleBase Clustrix HP NonStop IBM InfoSphere Warehouse editions that include the Database Partitioning Feature (formerly known as DB2 Extended Enterprise Edition) MarkLogic Greenplum Oracle NoSQL Database