1. 弹性搜索：
Elasticsearch 是一个分布式搜索和分析引擎。它是开源的，可用于所有类型的数据。它以Java编程语言实现，支持所有具有Java虚拟机 (JVM) 的操作系统。它是 Elastic Stack 的主要组件，Elastic Stack 是一个用于数据分析和可视化的开源应用程序。它具有很高的可扩展性，执行动作的速度也很高，这使其成为数据分析、处理和可视化的简单快捷的工具。
2. MongoDB：
MongoDB 是一个面向文档的数据库模型，它是一个开源软件。它由 MongoDB Inc. 于 2009 年开发，使用 C++ 语言实现。 MongoDB 使用像 JSON 这样的文档。它可以用作独立程序并提供备份功能。它的排名很高，在数据库中很受欢迎。它还包含用户定义的Java脚本函数。在 MongoDB 中，扩展是通过使用分片水平完成的。
IBM DB2 和 MongoDB 的区别：
| S.NO. | Elasticsearch | MongoDB | |||
|---|---|---|---|---|---|
| 1. | Elasticsearch is a search and analytics engine based on Apache Lucene. | MongoDB is a document oriented database model. | |||
| 2. | The primary database model is a search engine. | Primary database model is document store in MongoDB. | |||
| 3. | It has no concept of transactions. | It has concept of transactions satisfying ACID properties . | |||
| 4. | It was developed by ELASTIC in 2010. | It was developed by MongoDB Inc. in 2009. | |||
| 5. | It has SQL like query language. | It uses MongoDB connector by BI for queries. | |||
| 6. | It involves eventual consistency. | It involves immediate consistency. | |||
| 7. | It is implemented in java. | It is implemented in C++ language. | |||
| 8. | It has Java API, RESTful HTTP/JSON API. | It has proprietary protocol using JSON. | |||
| 9. | It is considered less than MongoDB in terms of ranking. | It is considered better than Elasticsearch in terms of ranking. | 10. | It accepts all operating systems having JVM. | It supports LINUX, OS X, Solaris, Windows. |