I have started a new job where I would be using elastic search. I want to learn as much as about elasticSearch so I can hit the ground running when I start work.
The aggregations framework helps provide aggregated data based on a search query. It is based on simple building blocks called aggregations, that can be composed in order to build complex summaries of the data.
metrics aggregations are a special type of metrics aggregation which output numeric values. For example: max, min, stats, avg etc.
Bucket aggregations don’t calculate metrics over fields like the metrics aggregations do, but instead, they create buckets of documents.
Furthermore, you can also combine bucket and metric aggregations to retrieve a mathematical aggregation within a bucket.
For example: Get me the average number of earthquakes occurred in North America. Where bucket is North America and the metric being used is avg.