Table 1 Key-value stores
From: Modeling temporal aspects of sensor data for MongoDB NoSQL database
Name | Data model | Scalability | Description | Who uses it |
|---|---|---|---|---|
Memcached from http://www.bradfitz.com [55] | Set of key-value in associative array | Auto sharding, no replication and persistency | In-memory cache systems, no disk persistence (MemcacheDB give persistent storage [56]); file system storage, ACID | LiveJournal, Wikipedia, Flickr, Bebo, Craigslist |
Aerospike from http://www.aerospike.com [49] | Associate keys with records (i.e rows); namespaces (for dataset) divide into sets (i.e tables); key index records | Auto partition, synch. replication | In-memory very fast database with disk persistence. ACID with relax options | AppNexus, Kayak, blueKai, Yashi, Chango |
Cassandra from facebook [57] | Hybrid of key-value and column-oriented models; Cassandra query language: SQL like model | Auto partition, synch. and asynch. replication | In-memory database with disk persistence; highly scalable | CERN, Comcast, eBay, Netflix, GitHub |
Redis from S. Sanfilippo [48] | Het of (key, value); complex types (string, binary, list, set, sorted set, hashes, arrays); key can be any binary e.g. JPEG | Auto partitioning, replication, persistent levels | Most popular in-memory with disk persistence; ACID; MapReduce through Jedis [58], \({r}^{3}\) [59] | Twitter, GitHub, Flickr, StackOverflow |
Riak [60] from Basho Technologies | Data types (flags, counter, sets, registers, maps, hyperlog) | Sharding, replication, master-less [61], backup and recovery | High available; Dynamo base [62]; in-memory with disk persistence; relax consistency; MapReduce, REST-full; enterprise and cloud versions; Riak KV base Riak TimeSeries [63] | AT and T, Comcast GitHub, UKHealth, weather channel |
Voldemort from LinkedIn [50] | Complex key-value compound objects (e.g. lists/maps); supported queries: get, put and delete; no complex query filters; simple api for persistence [64]; schema-evolution | Auto data partitioning and replication, versioning | In-memory with disk persistence, big fault-tolerant hash table; no ACID, pluggable serialization (e.g. avro, java) and storage engine (concurrentHashMap, mysql, BDB JE) | LinkedIn, Gilt |
DynamoDB from Amazon [65] | Dynamo [62] based to support both document and key-value models [65]; secondary indexes; DynamoDB Titan: integratable graph database | Replication, partitioning, highly available, versioning | Popular, two of the four ACID properties: consistency and durability; elastic MapReduce for Hadoop; AWS SDK to store JSON | Amazon, BMW, duolingo, lyft, redfin, adroll |