PACELC theorem

Database PACELC ratings are from The default versions of DynamoDB, Cassandra, Riak and Cosmos DB are PA/EL systems: if a partition occurs, they give up consistency for availability, and under normal operation they give up consistency for lower latency. Fully ACID systems such as VoltDB/H-Store, Megastore and MySQL Cluster are PC/EC: they refuse to give up consistency, and will pay the availability and latency costs to achieve it. BigTable and related systems such as HBase are also PC/EC. Cosmos DB supports five tunable consistency levels that allow for tradeoffs between C/A during P, and L/C during E. Cosmos DB never violates the specified consistency level, so it’s formally CP.

Distributed data store

distributed data storagedata storedatabases
Couchbase, data store used by LinkedIn, Paypal, Ebay and others. CrateIO. Druid (open-source data store), used by Netflix, Yahoo and others. Dynamo of Amazon. Hazelcast. HBase, current data store of Facebook's Messaging Platform. Hypertable, from Baidu. MongoDB. Riak. Scylla. Voldemort, data store used by LinkedIn. BitTorrent. Blockchain (database). Chord project. GNUnet. Freenet. Unity, of the software Perfect Dark. Mnet. NNTP (the distributed data storage protocol used for Usenet news). Storage@home. Tahoe-LAFS. IPFS. ZeroNet. STORJ. Cooperative storage cloud. Data store. Distributed file system. Keyspace, the DDS schema. Peer-to-peer. Distributed hash table. Distributed cache.

Database caching

Couchbase - Redis - Distributed in-memory database system, which also supports various distributed caching scenarios. CSQL Cache - To cache tables from MySQL, Postgres and Oracle. memcached- To cache result set of queries. Windows Azure Caching- To cache result set of queries in Windows Azure. TimesTen - To cache ORACLE tables. SafePeak - Automated caching of result sets of queries and procedures from SQL Server, with automated cache eviction for full data correctness. Apache Ignite. GridGain Systems. Tarantool - Open-source, in-memory cache DB with full Lua application server.


NewSQL databases
Example systems in this category are Amazon Aurora, Google Spanner, TiDB, CockroachDB, Altibase, Apache Ignite, Microsoft Cosmos DB, GridGain, Clustrix, VoltDB, MemSQL, NuoDB, HarperDB and Trafodion The second category are highly optimized storage engines for SQL. These systems provide the same programming interface as SQL, but scale better than built-in engines, such as InnoDB. Examples of these new storage engines include MySQL Cluster, Infobright, TokuDB, MyRocks, SQL Server (with ColumnStore and InMemory features), and MariaDB Columnstore. These systems provide a sharding middleware layer to automatically split databases across multiple nodes. Examples are ScaleBase and Vitess.

Google Cloud Datastore

Google Cloud
Azure Cosmos DB. Amazon DynamoDB. Oracle Cloud NoSQL DB. Official website. Google Cloud Platform site.

Big Data Partnership

Big Data Partnership provides expertise in platforms including Apache Hadoop, Apache Cassandra, Elasticsearch, Apache HBase, Apache Spark, Apache Storm and Couchbase. Big Data Partnership was founded in 2012 by Mike Merritt-Holmes, Pinal Gandhi and Tim Seears and formed partnerships with companies including Hortonworks, MapR, WANdisco, Databricks, Amazon Web Services, Intel and Elasticsearch. In June 2014, Big Data Partnership announced Series A funding led by Beringea LLP, an international venture capital firm with offices in London and Detroit. In 2016, Big Data Partnership was acquired by Teradata to join their ThinkBig practice.

List of FLOSS Weekly episodes

The following lists all the FLOSS Weekly shows that have been produced. There is a public list of potential future guests, although the show is only scheduled two months out.


The following projects have been started to replace or offer an alternative storage engines for already-established database systems with RocksDB: ArangoDB has added RocksDB to its previous storage engine ("mmfiles"). Starting with ArangoDB 3.4, RocksDB will be the default storage engine in ArangoDB. The MongoRocks project provides a storage module for MongoDB where the storage engine is RocksDB. A related program is Rocks Strata, a tool written in Go, which allows managing incremental backups of MongoDB when RocksDB is used as the storage engine. The MyRocks project creates a new RocksDB based storage engine for MySQL. In-depth details about MyRocks were presented at Percona Live 2016.

Consistent hashing

Some known instances where consistent hashing is used are: Couchbase automated data partitioning. Openstack's Object Storage Service Swift. Partitioning component of Amazon's storage system Dynamo. Data partitioning in Apache Cassandra. Data Partitioning in Voldemort. Akka's consistent hashing router. Riak, a distributed key-value database. GlusterFS, a network-attached storage file system. Skylable, an open-source distributed object-storage system. Akamai Content Delivery Network. Discord chat application. Maglev: A Fast and Reliable Software Network Load Balancer. Understanding Consistent hashing. Consistent hashing by Michael Nielsen on June 3, 2009.


Couchbase Server. LMDB. Memcached. GridGain Systems. Hazelcast. Redis. Tarantool.

Oracle Database

OracleOracle 10gOracle 8i
Increasingly, the Oracle database products compete against such open-source software relational database systems as PostgreSQL, MongoDB, and Couchbase. Oracle acquired Innobase, supplier of the InnoDB codebase to MySQL, in part to compete better against open source alternatives, and acquired Sun Microsystems, owner of MySQL, in 2010.

Lightning Memory-Mapped Database

FineDB is a NoSQL server built on LMDB, which compares itself, amongst others, with Redis, CouchBase, MongoDB. Extenium an ACID compliant NoSQL database is implemented on top of LMDB. The Apache module mod_authn_lmdb provides Apache user authentication using an LMDB as a credential store. The GNU Guile generic graph database sph-dg builds upon LMDB. InfluxDB a time series, events, and metrics database. urbackup employs LMDB as a cache backend. Knot DNS a high performance DNS server. Knot Resolver caching full resolver implementation, including both a resolver library and a daemon.

Select (SQL)

The SQL SELECT statement returns a result set of records from one or more tables.


Couchbase, Inc. also provides a Couchbase Server-Hadoop connector by means of Sqoop. Apache Hive. Apache Accumulo. HBase. Sqoop Wiki. Sqoop Users Mailing List Archives.

Cosmos (disambiguation)

Azure Cosmos DB, a database by Microsoft, previously called DocumentDB. Cosmos (operating system). COSMOS (telecommunications), a distribution frame record-keeping system. COS/MOS, a family of integrated circuits. CoSMoS, a genetic modelling research project. COSMOS, a molecular modelling software package. Cosmos, developer of a database based on the Pick operating system. New York Cosmos (1970–85), an American soccer club based in New York City. New York Cosmos (2010), an American soccer club based in New York City. AM Cosmos Ljubljana, a Slovenian football club from 1992–93; since renamed to NK Ljubljana. Canberra Cosmos FC, a former Australian football based in Canberra.

Semi-structured data

There is a new breed of databases such as MongoDB and Couchbase that store data natively in JSON format, leveraging the pros of semi-structured data architecture. Programmers persisting objects from their application to a database do not need to worry about object-relational impedance mismatch, but can often serialize objects via a light-weight library. Support for nested or hierarchical data often simplifies data models representing complex relationships between entities. Support for lists of objects simplifies data models by avoiding messy translations of lists into a relational data model. The traditional relational data model has a popular and ready-made query language, SQL.


Parallel Optimized Host Message Exchange Layered File System
Couchbase Server. Apache Cassandra. HBase. Riak. Elasticsearch. Memcached. Redis.

Google Cloud Platform

Google CloudGCPGoogle
Google Cloud Platform, offered by Google, is a suite of cloud computing services that runs on the same infrastructure that Google uses internally for its end-user products, such as Google Search and YouTube. Alongside a set of management tools, it provides a series of modular cloud services including computing, data storage, data analytics and machine learning. Registration requires a credit card or bank account details.

Java Persistence API

JPAJava PersistenceJPA 2.0
OrientDB from Orient Technologies. Versant Corporation JPA (not relational, object database). Converters - allowing custom code conversions between database and object types. Criteria Update/Delete - allows bulk updates and deletes through the Criteria API. Entity Graphs - allow partial or specified fetching or merging of objects. JPQL/Criteria enhancements - arithmetic sub-queries, generic database functions, join ON clause, TREAT option. Schema Generation. Stored Procedures - allows queries to be defined for database stored procedures. DataNucleus. EclipseLink. Hibernate. Add @Repeatable to all relevant annotations. Allow all JPA annotations to be used in meta-annotations.

List of Java frameworks

List of Java technologies
Below is a list of Java programming language technologies (frameworks, libraries)

Azure Stream Analytics

Support for Azure Table Storage, Azure SQL Databases, Azure SQL Data Warehouse, Azure SQL, Document DB, Azure Data Lake Store enable a variety of downstream analysis and archiving capabilities.