Difference between Adabas and Couchbase

1. Adabas :
The Adabas stands for an Adaptable Database System. It was developed by Software AG to run on IBM mainframes. It was launched in 1971. It is an OLTP-DBMS for mainframes and Linux/Unix/Windows environments. ADABAS is an enterprise database management system (DBMS) designed for reliability, high performance, scalability and low total cost of ownership.

2. Couchbase :
Couchbase Server is an open-source, distributed multi-model NoSQL document-oriented database software package that is optimized for interactive applications. It is also known as Membase. It was developed by Couchbase, Inc. and initially released in August 2010.

Difference between Adabas and Couchbase :

S.No.	ADABAS	Couchbase
1.	It was developed By Software AG in 1971.	It was developed by Couchbase, Inc. and initially released in August 2011.
2.	It is an OLTP-DBMS for mainframes and Linux/Unix/Windows environments.	It is a JSON-based document store derived from CouchDB with a Memcached-compatible interface.
3.	Adabas is written in Natural language.	Couchbase is written in C++, Erlang, C and Go languages.
4.	Server operating systems for Adabas are BS2000, Linux, Unix, Windows, z/OS and z/VSE.	Server operating systems for Couchbase are Linux, OS X and Windows.
5.	It supporta Data schema.	It is schema free.
6.	Server-side scripting is done in Natural language.	It has functions and timers in JavaScript for Server-side scripts.
7.	It supports partitioning methods.	In Couchbase, partitioning can be done by sharding.
8.	It supports SQL query language with add-on product Adabas SQL Gateway.	It supports Declarative query language (N1QL) that extends ANSI SQL to JSON. First commercial implementation of SQL++.
9.	It supports Replication with add-on product Event Replicator.	It support two replication methods : Master-master replication and Master-slave replication.
10.	Adabas does not provide the concept of Referential Integrity. Hence, no Foreign Keys.	Couchbase also does not provide the concept of Referential Integrity. Hence, no Foreign Keys.
11.	The license of Adabas is commercial.	The license of Couchbase is open-source.
12.	The primary database model of Adabas is Multivalue DBMS.	The primary database models of Couchbase is Document store.
13.	It does not support in-memory capabilities.	It supports in-memory capabilities.