Elasticsearchとは

Highly scalable full-text search engine developed by Elastic
Enables various analysis such as real time data analysis, log analysis, full text search
Often used with log aggregation Logstash and fluentd, and visualization tools kibana
Searching across multiple databases is provided as a common use

Elasticsearch
– Strong search performance and scalability
– Indexes are often separated by time intervals
– Throw away indexes that are no longer needed
– Store data for analysis and search

RDS:Elasticsearch
DB -> index
table -> mapping type
column -> field
record -> document

Mapping: Setting of field type and analysis method
Analysis: About processing of field values such as language processing and normalization
Query DSL: Assembling search condition in JSON format