Using the MemoryStore
The MemoryStore provides an in-memory, table-based, data storage abstraction within the correlator. All EPL code running in the correlator in any context can access the data stored by the MemoryStore. In other words, all EPL monitors running in the correlator have access to the same data.
The Apama MemoryStore can also be used in a distributed fashion to provide access to data stored in a MemoryStore to applications running in a cluster of multiple correlators. For more information on the distributed MemoryStore, see
Using the distributed MemoryStore.
The MemoryStore can also store data on disk to make it persistent, and copy persistent data back into memory. However, the MemoryStore is primarily intended to provide all monitors in the correlator with in-memory access to the same data.
Use the MemoryStore to share data among monitors in the correlator or to persist data on disk. If the situations listed below apply to you, the standard Apama ADBC (Apama Database Connector) adapter is likely to be a better option for you than the MemoryStore.
You want to interoperate directly with data users other than Apama.
You need access to more data than can fit in memory.
You need to key on more than one field.
You want to join tables.
For details about the event types that provide the MemoryStore interface, see the
API Reference for EPL (ApamaDoc) .