Concepts

If you are relatively new to BTrDB, then there are a few things you should be aware of about interacting with the server. First of all, time series databases such as BTrDB are not relational databases and so they behave differently, have different access methods, and provide different guarantees.

The following sections provide insight into the high level objects and aspects of their behavior which will allow you to use them effectively.

BTrDB Server

Like most time series databases, the BTrDB server contains multiple streams of data in which each stream contains a data point at a given time. However, BTrDB focuses on univariate data which opens a host of benefits and is one of the reasons BTrDB is able to process incredibly large amounts of data quickly and easily.

Points

Points of data within a time series make up the smallest objects you will be dealing with when making calls to the database. Because there are different types of interactions with the database, there are different types of points that could be returned to you: :code:RawPoint and :code:StatPoint.

RawPoint

The RawPoint represents a single time/value pair and is the simpler of the two types of points. This is most useful when you need to process every single value within the stream.

StatPoint

The StatPoint provides statistics about multiple points and gives aggregation values such as min, max, mean, etc. This is most useful when you don't need to touch every individual value such as when you only need the count of the values over a range of time.

These statistical queries execute in time proportional to the number of results, not the number of underlying points (i.e logarithmic time) and so you can attain valuable data in a fraction of the time when compared with retrieving all of the individual values. Due to the internal data structures, BTrDB does not need to read the underlying points to return these statistics!

Streams

Streams represent a single series of time/value pairs. As such, the database can hold an almost unlimited amount of individual streams. Each stream has a collection which is similar to a "path" or grouping for multiple streams. Each steam will also have a name as well as a uuid which is guaranteed to be unique across streams.

BTrDB data is versioned such that changes to a given stream (time series) will result in a new version for the stream. In this manner, you can pin your interactions to a specific version ensuring the values do not change over the course of your interactions. If you want to work with the most recent version/data then specify a version of zero (the default).

Each stream has a number of attributes and methods available and these are documented within the API section of this publication. But the most common interactions by users are to access the UUID, tags, annotations, version, and underlying data.

Each stream uses a UUID as its unique identifier which can also be used when querying for streams. Metadata is provided by tags and annotations which are both provided as dictionaries of data. Tags are used internally and have very specific keys while annotations are more free-form and can be used by you to store your own metadata.