Aerospike vs VoltDB: What are the differences?

Aerospike: Flash-optimized in-memory open source NoSQL database. Aerospike is an open-source, modern database built from the ground up to push the limits of flash storage, processors and networks. It was designed to operate with predictable low latency at high throughput with uncompromising reliability – both high availability and ACID guarantees; VoltDB: In-memory relational DBMS capable of supporting millions of database operations per second. VoltDB is a fundamental redesign of the RDBMS that provides unparalleled performance and scalability on bare-metal, virtualized and cloud infrastructures. VoltDB is a modern in-memory architecture that supports both SQL + Java with data durability and fault tolerance.

Aerospike and VoltDB can be primarily classified as "In-Memory Databases" tools.

Some of the features offered by Aerospike are:

• 99% of reads/writes complete in under 1 millisecond.
• Predictable low latency at high throughput – second to none. Read the YCSB Benchmark.
• The secret sauce? A thousand things done right. Server code in ‘C’ (not Java or Erlang) precisely tuned to avoid context switching and memory copies. Highly parallelized multi-threaded, multi-core, multi-cpu, multi-SSD execution.

On the other hand, VoltDB provides the following key features:

• In-Memory Performance with On-Disk Durability
• Transparent Scalability with Data Consistency
• NewSQL – All the benefits of SQL with Unlimited Scalability

"Ram and/or ssd persistence " is the primary reason why developers consider Aerospike over the competitors, whereas "SQL + Java" was stated as the key factor in picking VoltDB.

Aerospike is an open source tool with 295 GitHub stars and 54 GitHub forks. Here's a link to Aerospike's open source repository on GitHub.