# SingleStore

SingleStore (formerly MemSQL) is a distributed, relational, SQL database management system (RDBMS) that features ANSI SQL support, it is known for speed in data ingest, transaction processing, and query processing.
SingleStore stores relational data, JSON data, geospatial data, key-value vector data, and time series data. It can be run in various Linux environments, including on-premises installations, public and private cloud providers, in containers via a Kubernetes operator, or as a hosted service in the cloud known as SingleStore Helios.
Recent updates have included bi-directional integration with Apache Iceberg, faster vector search, enhanced full-text search, autoscaling and a ‘bring your own cloud’ deployment. In its latest release, v.8.9, SingleStore added support for continuous ingest from Iceberg tables, as well as Polaris and Hive catalogs, support for foreign languages as well as n-grams in full-text search; simplified pipelines; a no-code interface that simplifies data ingestion from S3, CSV and MongoDB sources; and disk spilling that now works on right and full join, as well as writable views and vector indexes on nullable columns.

## History

On April 23, 2013, SingleStore launched its first generally available version of the database to the public as MemSQL. Early versions supported row-oriented tables, and were optimized for cases where all data fit within main memory. This design was based on the idea that the cost of RAM would continue to decrease exponentially over time, in a trend similar to Moore's law. This would eventually allow most use cases for database systems to store their data exclusively in memory.
Shortly after launch, MemSQL added general support for an on-disk column-based storage format to work alongside the in-memory rowstore.
On October 27, 2020, MemSQL rebranded to SingleStore to reflect a shift in focus away from exclusively in-memory workloads.
In April 2023, SingleStore introduced new features to enhance real-time AI capabilities, focusing on faster data processing and more efficient AI-driven applications. In May, the company introduced additional tools aimed at enhancing generative AI (GenAI) and analytics capabilities. The update included features designed to improve data processing, scalability, and performance, enabling more efficient analytics and AI-driven insights for complex data workloads.
In July 2023, SingleStore announced a partnership with AWS to advance real-time data analytics and AI applications.
In August 2023, IBM announced a collaboration with SingleStore to integrate its watsonx.ai platform for developing generative AI applications.
In January 2024, SingleStore announced a new capability under the name SingleStore Kai that added MongoDB API compatibility to SingleStore allowing users to bring in data from MongoDB and run the same queries within SingleStore.
In September 2024, SingleStore announced its integration with Snowflake by making SingleStore available as a Snowflake Native App in the Snowpark Container Services (SPCS) marketplace.
In October 2024, the company announced the acquisition of BryteFlow, a leading data integration platform. The move expanded SingleStore’s capacity to ingest data from a wide range of sources like SAP, Oracle, Salesforce, and many more, enabling customers to operationalize data from their CRM and ERP systems at scale and in real time.
Headquartered in San Francisco, California, in June 2021 SingleStore opened an office in Raleigh, North Carolina. Its other offices include Sunnyvale, California; Seattle, Washington; London, England; Hyderabad, India; and Lisbon, Portugal.

### Funding

In January 2013, SingleStore announced it raised $5 million. Since then, the company has raised $318.1M from investors including Khosla Ventures, Accel, Google Ventures, Dell Capital and HPE, among others. In October 2022, SingleStore closed Series F-2 and welcomed new investor Prosperity7.
Funding Rounds :
| Series | Date | Amount (million $) | Lead Investors |
| A | 2013 | 5 | DVCA, IA Ventures |
| B | 2014 | 35 | Accel |
| C | 2016 | 36 | Caffeinated Capital, REV |
| D | 2018 | 30 | Google Ventures, Glynn Capital |
| E | Dec. 2020 | 80 | Insight Partners |
| F | Sept. 2021 | 80 | Insight Partners |
| G | July 2022 | 116 | Goldman Sachs Asset Management |
| F-2 | October 2022 | 30 | Prosperity7 |

## Architecture
### Row and column table formats

SingleStore can store data in either row-oriented tables ("rowstores") or column-oriented tables ("columnstores"). The format used is determined by the user when creating the table.
Rowstore tables, as the name implies, store information in row format, which is the traditional data format used by RDBMS systems. Rowstores are optimized for singleton or small insert, update, or delete queries and are most closely associated with OLTP (transactional) use cases. Data for rowstore tables is stored completely in-memory, making random reads fast, with snapshots and transaction logs persisted to disk. Columnstores are optimized for complex SELECT queries, typically associated with OLAP (analytics) and data warehousing use cases.

### Indexing

Rather than the traditional B-tree index, SingleStore rowstores use skiplists optimized for fast, lock-free processing in memory. Columnstores store data in sorted segments, in order to maximize on-disk compression and achieve fast ordered scans. SingleStore also supports using hash indexes as secondary indexes to speed up certain queries.

### Distributed architecture

A SingleStore database is distributed across many nodes, which may be cloud-based servers or commodity machines. Data is stored in partitions on leaf nodes, and users connect to aggregator nodes. A single piece of software is installed for SingleStore aggregator and leaf nodes; administrators designate each machine’s role in the cluster during setup. An aggregator node is responsible for receiving SQL queries, breaking them up across leaf nodes, and aggregating results back to the client. A leaf node stores SingleStore data and processes queries from the aggregator(s). All communication between aggregators and leaf nodes is done over the network using SQL. SingleStore uses hash partitioning to distribute data uniformly across the number of leaf nodes.

### Durability

Durability for the in-memory rowstore is implemented with a write-ahead log and snapshots, similar to checkpoints. With default settings, as soon as a transaction is acknowledged in memory, the database will asynchronously write the transaction to disk as fast as the disk allows.

### Replication

A SingleStore cluster can be configured in "High Availability" (HA) mode, where every data partition is automatically created with primary and replica partitions on two separate leaf nodes. In HA mode, aggregators send transactions to the primary partitions, which then send logs to the secondary partitions. In the event of an unexpected primary failure, the replica partitions take over as primary partitions, in a fully online operation with no downtime.

### Iceberg support and vector search

In 2024, SingleStore updated its architecture to include support for Apache Iceberg, enabling more efficient data lake management and querying. The release also added enhanced full-text search for more efficient data retrieval, autoscaling for better resource management, and a "bring your own cloud" deployment option, offering users greater flexibility in cloud infrastructure choices.

## Distribution formats

SingleStore can be downloaded for free and run on Linux for systems up to 4 leaf nodes of 32 gigs RAM each; an Enterprise license is required for larger deployments and for official SingleStore support.SingleStore is also available as a managed service named SingleStore Helios, available in various regions in Google Cloud and Amazon Web Services. The underlying engine and potential system performance are identical in all distribution formats.
SingleStore includes a set of tools, called SingleStore Tools, for installing, managing, and monitoring its distributed database across multiple machines. It also offers a browser-based interface, SingleStore Studio, for running queries, monitoring the database, and viewing cluster health and status.

## Recognition

In 2024, SingleStore was recognized with five TrustRadius Top Rated Awards. SingleStore also earned a 2025 Buyer’s Choice Award from TrustRadius.
In December 2021, SingleStore was recognized in the Gartner Magic Quadrant for Cloud Database Management System for the second time in its history; the company first earned the recognition in 2021.