OLTP

Short for Online Transaction Processing — the "normal" database, optimised for lots of small reads and writes to an application's live state: creating a user, saving a form, loading one record. This is what's running behind almost every self-hosted app in this catalog.

App	License	FOSS problems	SSO	Users	Tested
PostgreSQLGeneral-purpose relational database with strong standards compliance, JSONB, and an extension ecosystem covering geospatial and vector search.	PostgreSQL LicensePermissive license. An MIT/BSD-style permissive license — use, modify, and redistribute freely, including in proprietary products, with no obligation to share changes.	—	—	Unlimited	✅
MariaDBCommunity-governed fork of MySQL, created after Oracle's acquisition of Sun Microsystems, staying close to drop-in compatible.	GPLv2Copyleft license. If you distribute it, modified or not, you must publish the source under GPLv2 too. No network-service clause — running it as a hosted service doesn't trigger that.	—	—	Unlimited	❌
MySQLWidely deployed relational database, dual-licensed and owned by Oracle since its 2010 acquisition of Sun Microsystems.	GPLv2Copyleft license. If you distribute it, modified or not, you must publish the source under GPLv2 too. No network-service clause — running it as a hosted service doesn't trigger that.	Dual-licensed, Oracle-owned, commercial tier gated behind a separate license	—	Unlimited	❌
SQLiteSelf-contained, serverless, file-based database engine — the whole database is one file, with no separate server process to run.	Public DomainPublic domain license. No rights reserved — copyright is waived entirely. No conditions, no attribution required, use it however you want.	—	—	Unlimited	❌