Learning Elastic Stack 6.0

Selecting hardware

Elasticsearch primarily has memory-bound tasks which rely on the inverted index. The more data that it can fit in the RAM, the faster the performance will be. But this statement can not always be generalized. It depends on the nature of your data and the type of operations or workload that you are going to have.

Using Elasticsearch doesn't mean that it has to perform all operations in-memory. Elasticsearch also uses on-disk data very efficiently, especially for aggregation operations.

All datatypes (except analyzed strings) support a special data structure called doc_values, which organizes the data on the disk in a columnar fashion. doc_values is useful for sorting and aggregation operations. Since doc_values are enabled ...