- Document is a unit of storage, indexing, search, and aggregation
- 3rd form of normalization (or beyond) does not apply to ElasticSearch
- ElasticSearch supports no join or its equivalents
- Document indexing, searching, and aggregation uses no locks
- ElasticSearch designed for scalability
- Application side joins: a no-no in a Rdbms world and is a common practice in NoSql world
- Data de-normalization: redundant copies of data in each document removes the need for joins
- Nested objects: storing parent and child data in a single document
- Parent-Child Relationship: storing child documents separately and are associated with the parent document
- ElasticSearch lacks built-in mechanism for de-normalized data maintenance, so are many other NoSql