Chapter 7. Advanced Topics for Time Series Databases
So far, we have considered how time series can be stored in databases where each time series is easily identified: possibly by name, possibly by a combination of tagged values. The applications of such time series databases are broad and cover many needs.
There are situations, however, where the time series databases that we have described so far fall short. One such situation is where we need to have a sense of location in addition to time. An ordinary time series database makes the assumption that essentially all queries will have results filtered primarily based on time. Put another way, time series databases require to you specify which metric and when the data was recorded. Sometimes, however, we need to include the concept of where. We may want to specify only where and when without specifying which. When we make this change to the queries that we want to use, we move from having a time series database to having a geo-temporal database.
Note that it isn’t the inclusion of locational data into a time series database per se that makes it into a geo-temporal database. Any or all of latitude, longitude, x, y, or z could be included in an ordinary time series database without any problem. As long as we know which time series we want and what time range we want, this locational data is just like any other used to identify the time series. It is the requirement that location data be a primary part of querying the database that makes ...