Binary Behaviour Dataset

This feature is part of the MLDB Pro Plugin and so can only be used in compliance with the trial license unless a commercial license has been purchased

The Behaviour Dataset is used to store pure binary behavioural data. It can only store the value 1, but is extremely efficient for working with lots of rows and columns. It records timestamps with a resolution of one second.

It can be memory mapped, which allows it to work with data that is larger than memory.

It is designed for the following situations:

• Datasets with up to hundreds of millions of rows.
• Datasets with up to millions of columns.
• For datasets where there are a lot more rows than columns. For example, when rows represent users and columns represent things that they have done.
• Very sparse data, with a density factor of less than one percent.
• To store discrete values, not continuous values. For example if you need to record purchase price, put it in a price bucket rather than recording the actual price.

It stores its data in a binary file format, normally with an extension of .beh, which is specified by the dataFileUrl parameter. This file format is allows full random access to both the matrix and its inverse and is very efficient in memory usage.

This dataset type is read-only, in other words it can only load up datasets that were previously written from a legacy system.

Configuration

A new dataset of type beh.binary named <id> can be created as follows:

mldb.put("/v1/datasets/"+<id>, {
    "type": "beh.binary",
    "params": {
        "dataFileUrl": <Url>
    }
})

with the following key-value definitions for params:

Routes

The binary behaviour dataset exposes a saves route, which allows the dataset to be saved to a given artifact URL. This route has one single parameter passed in the JSON body: dataFileUrl which is the URL of where the artifact (.beh file) should be saved.

See also

• The beh.binary.mutable dataset type is a mutable counterpart.
• The beh dataset type uses the same file format but allows values that aren't 1 to be stored.