Abstract: Improved storage systems which use write off-loading are described. When a request to store some data in a particular storage location is received, if the particular storage location is unavailable, the data is stored in an alternative location. In an embodiment, the particular storage location may be unavailable because it is powered down or because it is overloaded. The data stored in the alternative location may be subsequently recovered and written to the particular storage location once it becomes available.

Abstract: A prediction system may perform capacity planning for one or more resources of a database systems, such as by understanding how different workloads are using the system resources and/or predicting how the performance of the workloads will change when the hardware configuration of the resource is changed and/or when the workload changes. The prediction system may use a detailed, low-level tracing of a live database system running an application workload to monitor the performance of the current database system. In this manner, the current monitoring traces and analysis may be combined with a simulation to predict the workload's performance on a different hardware configuration. More specifically, performance may be indicated as throughput and/or latency, which may be for all transactions, for a particular transaction type, and/or for an individual transaction.