In-Memory Database

An in-memory database (IMDb, or main memory database system (MMDB) or memory resident database) is a database management system that primarily relies on main memory for computer data storage. It is contrasted with database management systems that employ a disk storage mechanism. In-memory databases are faster than disk-optimized databases because disk access is slower than memory access and the internal optimization algorithms are simpler and execute fewer CPU instructions.

Architectural Decision Record

In software engineering and software architecture design, architectural decisions are design decisions that address architecturally significant requirements; they are perceived as hard to make and/or costly to change. Architectural decisions influence and impact the non-functional characteristics of a system. Each architectural decision describes a concrete, architecturally significant design issue (a.k.a. design problem, decision required) for which several potential solutions.

Heart Rate Variability

Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval. Other terms used include "cycle length variability", "R–R variability" (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive Rs), and "heart period variability".