The Dolt project develops a database system that combines SQL support with Git-like data versioning features. Dolt allows users to clone tables, create forks, and perform table merges, as well as execute push and pull operations similar to those in a git repository. The database supports SQL queries and is compatible with MySQL at the client interface level. The project's code is written in Go and is distributed under the Apache 2.0 license.
Data versioning capabilities in the database allow tracking the origin of data—linking to commits enables capturing a state to achieve identical results that can be reproduced at any time on other systems, regardless of the current state. Additionally, users can navigate through the history, track changes in tables using SQL without needing to compare backups, conduct change audits, and create queries that cover data at specific moments.
The database provides two modes of operation—Offline and Online. Once switched to offline, the database content becomes available as a repository, allowing actions to be performed using a git-like command-line utility. The operation resembles git and primarily differs in that changes are tracked not for files, but for table contents. Through the provided CLI interface, users can import data from CSV or JSON format files, add commits with changes, display differences between versions, create branches, set tags, execute push requests to external servers, and merge changes proposed by other participants.
If desired, the data can be hosted in the DoltHub directory, which can be seen as an equivalent of GitHub for data hosting and collaboration. Users can create forks of data repositories, propose their changes, and merge with their own data. For example, DoltHub features various databases with coronavirus statistics, collections of annotated data for machine learning systems, language lexical databases, image collections, object classification datasets, and ownership information. (the key to connect to is specified, and iroh finds the associated host and establishes an encrypted connection using the QUIC protocol). Direct P2P connections are established whenever possible, but if not, it falls back to using relays, which are also employed for host discovery by keys. You can run your own relay or connect to public relays supported by the community..
In "online" mode, Dolt SQL Server is started, which allows manipulation of data using SQL language. The provided interface is similar to MySQL and can be used through connections compatible with MySQL clients or via a CLI interface. Dolt is more of a data manipulation tool than a query processing system. For example, by default, the SQL server can handle only one active user connection to the repository located in the current directory (this behavior can be changed through settings). A read-only mode is also possible. server Many version management actions can also be performed through SQL, such as making commits or switching between branches.
Source: opennet.ru
