This article provides an overview of aggregations and calculated fields.
Aggregations are functions for grouping multiple events together to form a more significant result, and they can return a single value or a hash table depending on the function.
Unlike databases, Upsolver runs continuous queries and not ad-hoc queries. Therefore, aggregation results are incrementally updated with every incoming event, and aggregation functions require windowing to split a stream into buckets of data that can be aggregated.
A calculated field is a field that wasn't part of an incoming event but is added into the event by using one of Upsolver's functions.
- extracting city from IP
- running a regular expression
- performing a mathematical operation
Please note that:
Calculated fields do not create any physical storage. They are executed at run-time if they are needed in a deployed lookup table or output.
Functions input parameters are limited to fields in the incoming event, constant values, and other calculated fields. It's possible to use fields from various hierarchical locations.
Functions output parameter is a single value or an array that can be placed at any hierarchical location within the event.
Functions are built to handle both single values and arrays so be sure to check each one in the documentation.