OLTP transaction workloads require quick access and updates to a small set of records. This work is typically performed in a localized area on disk, with one or a small number of parallel units. Shared-everything architectures, in which processors share a single large disk and memory, are well suited to OLTP workloads. Shared-disk architectures, such as Oracle RAC, can also be effective for OLTP because each server can take a subset of the queries and process them independently while ensuring consistency through the shared-disk subsystem. However, shared-everything and shared-disk architectures are quickly overwhelmed by the full-table scans, multiple complex table joins,.
