DBMS > Datomic vs. Realm vs. RocksDB vs. Snowflake vs. VelocityDB

System Properties Comparison Datomic vs. Realm vs. RocksDB vs. Snowflake vs. VelocityDB

Editorial information provided by DB-Engines

Name

Description

Datomic builds on immutable values, supports point-in-time queries and uses 3rd party systems for durability

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

Embeddable persistent key-value store optimized for fast storage (flash and RAM)

Cloud-based data warehousing service for structured and semi-structured data

A .NET Object Database that can be embedded/distributed and extended to a graph data model (VelocityGraph)

Primary database model

Graph DBMS
Object oriented DBMS

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

Score	1.55
Rank	#144	Overall
	#67	Relational DBMS

Score	7.18
Rank	#52	Overall
	#8	Document stores

Score	2.84
Rank	#97	Overall
	#16	Key-value stores

Score	133.72
Rank	#7	Overall
	#5	Relational DBMS

Score	0.00
Rank	#385	Overall
	#40	Graph DBMS
	#21	Object oriented DBMS

Website

Technical documentation

docs.datomic.com

realm.io/docs

github.com/facebook/rocksdb/wiki

docs.snowflake.net/manuals/index.html

velocitydb.com/UserGuide

Developer

Cognitect

Realm, acquired by MongoDB in May 2019

Facebook, Inc.

Snowflake Computing Inc.

VelocityDB Inc

Initial release

2012

2014

2013

2014

2011

Current release

1.0.7180, July 2024

9.4.0, June 2024

7.x

License

Commercial or Open Source

commercial

limited edition free

Open Source

BSD

commercial

Cloud-based only

Only available as a cloud service

yes

DBaaS offerings (sponsored links)

Database as a Service

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

Implementation language

Java, Clojure

C++

Server operating systems

All OS with a Java VM

Android
Backend: server-less
iOS
Windows

Linux

hosted

Any that supports .NET

Data scheme

yes

schema-free

yes

support of semi-structured data formats (JSON, XML, Avro)

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.

yes

Secondary indexes

yes

SQL

Support of SQL

yes

APIs and other access methods

RESTful HTTP API

C++ API
Java API

CLI Client
JDBC
ODBC

.Net

Supported programming languages

Clojure
Java

.Net
Java

with Android only
Objective-C
React Native
Swift

C
C++
Go
Java
Perl
Python
Ruby

JavaScript (Node.js)
Python

.Net

Server-side scripts

Stored procedures

yes

Transaction Functions

runs within the applications so server-side scripts are unnecessary

user defined functions

Triggers

By using transaction functions

yes

Change Listeners

similar concept for controling cloud resources

Callbacks are triggered when data changes

Partitioning methods

Methods for storing different data on different nodes

none

But extensive use of caching in the application peers

none

horizontal partitioning

yes

Sharding

Replication methods

Methods for redundantly storing data on multiple nodes

none

But extensive use of caching in the application peers

none

yes

MapReduce

Offers an API for user-defined Map/Reduce methods

Consistency concepts

Methods to ensure consistency in a distributed system

Immediate Consistency

Foreign keys

Referential integrity

yes

Transaction concepts

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

ACID

yes

ACID

Concurrency

Support for concurrent manipulation of data

yes

Durability

Support for making data persistent

yes

using external storage systems (e.g. Cassandra, DynamoDB, PostgreSQL, Couchbase and others)

yes

In-memory capabilities

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

yes

recommended only for testing and development

yes

In-Memory realm

yes

User concepts

Access control

yes

Users with fine-grained authorization concept, user roles and pluggable authentication

Based on Windows Authentication

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