DBMS > etcd vs. FatDB vs. OpenSearch vs. Percona Server for MongoDB vs. Realm

System Properties Comparison etcd vs. FatDB vs. OpenSearch vs. Percona Server for MongoDB vs. Realm

Editorial information provided by DB-Engines

Name

FatDB/FatCloud has ceased operations as a company with February 2014. FatDB is discontinued and excluded from the ranking.

Description

A distributed reliable key-value store

A .NET NoSQL DBMS that can integrate with and extend SQL Server.

A distributed, RESTful search and analytics engine forked from Elasticsearch and based on Apache Lucene

A drop-in replacement for MongoDB Community Edition with enterprise-grade features.

A DBMS built for use on mobile devices that’s a fast, easy to use alternative to SQLite and Core Data

Primary database model

Key-value store

Document store
Key-value store

Search engine

Document store

Secondary database models

Vector DBMS

DB-Engines Ranking measures the popularity of database management systems
Trend Chart

Score	7.03
Rank	#54	Overall
	#5	Key-value stores

Score	16.03
Rank	#37	Overall
	#4	Search engines

Score	0.60
Rank	#246	Overall
	#39	Document stores

Score	7.41
Rank	#52	Overall
	#8	Document stores

Website

etcd.io
github.com/etcd-io/etcd

github.com/opensearch-project
opensearch.org

www.percona.com/mongodb/software/percona-server-for-mongodb

realm.io

Technical documentation

etcd.io/docs
github.com/etcd-io/etcd/tree/master/Documentation

opensearch.org/docs/latest

docs.percona.com/percona-distribution-for-mongodb

realm.io/docs

Developer

FatCloud

Amazon Web Services

Percona

Realm, acquired by MongoDB in May 2019

Initial release

2012

2021

2015

2014

Current release

3.4, August 2019

2.5.0, January 2023

3.4.10-2.10, November 2017

License

Commercial or Open Source

Open Source

Apache Version 2.0

commercial

Open Source

Apache Version 2.0

Open Source

GPL Version 2

Open Source

Cloud-based only

Only available as a cloud service

DBaaS offerings (sponsored links)

Database as a Service

Providers of DBaaS offerings, please contact us to be listed.

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Implementation language

Java

C++

Server operating systems

FreeBSD
Linux
Windows

experimental

Windows

All OS with a Java VM

Linux

Android
Backend: server-less
iOS
Windows

Data scheme

schema-free

Flexible type definitions. Once a type is defined, it is persistent

schema-free

yes

Typing

predefined data types such as float or date

yes

XML support

Some form of processing data in XML format, e.g. support for XML data structures, and/or support for XPath, XQuery or XSLT.

Secondary indexes

yes

All search fields are automatically indexed

yes

SQL

Support of SQL

Via inetgration in SQL Server

SQL-like query language

APIs and other access methods

gRPC
JSON over HTTP

.NET Client API
LINQ
RESTful HTTP API
RPC
Windows WCF Bindings

Java API
RESTful HTTP/JSON API

proprietary protocol using JSON

Supported programming languages

.Net
C
C++
Clojure
Erlang
Go
Haskell
Java
JavaScript (Node.js)
Perl
PHP
Python
R
Ruby
Rust
Scala
Tcl

Go
Java
JavaScript (Node.js)
PHP
Python
Ruby

Elasticsearch client

Actionscript
C
C#
C++
Clojure
ColdFusion
D
Dart
Delphi
Erlang
Go
Groovy
Haskell
Java
JavaScript
Lisp
Lua
MatLab
Perl
PHP
PowerShell
Prolog
Python
R
Ruby
Scala
Smalltalk

.Net
Java

with Android only
Objective-C
React Native
Swift

Server-side scripts

Stored procedures

yes

via applications

yes

JavaScript

runs within the applications so server-side scripts are unnecessary

Triggers

yes, watching key changes

yes

via applications

yes

by using the 'percolation' feature

yes

Change Listeners

Partitioning methods

Methods for storing different data on different nodes

Sharding

none

Replication methods

Methods for redundantly storing data on multiple nodes

Using Raft consensus algorithm to ensure data replication with strong consistency among multiple replicas.

selectable replication factor

yes

Source-replica replication

none

MapReduce

Offers an API for user-defined Map/Reduce methods

yes

Consistency concepts

Methods to ensure consistency in a distributed system

Immediate Consistency

Eventual Consistency
Immediate Consistency

Eventual Consistency

Synchronous doc based replication. Get by ID may show delays up to 1 sec. Configurable write consistency: one, quorum, all

Eventual Consistency
Immediate Consistency

Immediate Consistency

Foreign keys

Referential integrity

Transaction concepts

Support to ensure data integrity after non-atomic manipulations of data

ACID

Concurrency

Support for concurrent manipulation of data

yes

Durability

Support for making data persistent

yes

In-memory capabilities

Is there an option to define some or all structures to be held in-memory only.

yes

via In-Memory Engine

yes

In-Memory realm

User concepts

Access control

Can implement custom security layer via applications

Access rights for users and roles

yes

More information provided by the system vendor

Specific characteristics

OpenSearch is a highly scalable and extensible open-source software suite for search,...
» more

Competitive advantages

Distributed as fully open source under Apache License, Version 2.0 (ALv2), OpenSearch...
» more

Typical application scenarios

The OpenSearch platform is used across a broad range of search , analytics, and observability...
» more

Licensing and pricing models

The OpenSearch Project offers open source software licensed under Apache License...
» more

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