Table of Contents
MobilityDB is an extension of PostgreSQL and PostGIS that provides temporal types. Such types are data types that represent the evolution on time of values of some element type, called the base type of the temporal type. For instance, temporal integers may be used to represent the evolution on time of the number of employees of a department. In this case, the data type is “temporal integer” and “integer” is the base type. Similarly, a temporal float may be used to represent the evolution on time of the temperature of a room. As another example, a temporal point may be used to represent the evolution on time of the location of a car, as reported by GPS devices. Temporal types are useful because representing values that evolve in time is essential in many applications, for example in mobility applications. Furthermore, the operators on the base types (such as arithmetic operators and aggregation for integers and floats, spatial relationships and distance for geometries) can be intuitively generalized when the values evolve in time.
MobilityDB provides the following temporal types:
tgeogpoint. These temporal types are based, respectively, on the
text base types provided by PostgreSQL, and on the
geography base types provided by PostGIS (restricted to 2D or 3D points). Furthermore, MobilityDB uses four time types to represent extents of time: the
timestamptz type provided by PostgreSQL and three new types which are
periodset. In addition, two range types are defined in MobilityDB:
The MobilityDB Project Steering Committee (PSC) coordinates the general direction, release cycles, documentation, and outreach efforts for the MobilityDB project. In addition, the PSC provides general user support, accepts and approves patches from the general MobilityDB community and votes on miscellaneous issues involving MobilityDB such as developer commit access, new PSC members or significant API changes.
The current members in alphabetical order and their main responsibilities are given next:
 Although 4D temporal points can be represented, the M dimension is currently not taken into account.