Event

<p>The success of open source databases like PostgreSQL and MySQL/MariaDB has created an ecosystem of derivatives claiming "drop-in compatibility." But as the distance between upstream and these derivatives grows, user confusion and brand dilution can follow.</p> <p>To address this, we explore the challenge of compatibility with de facto standards from two distinct angles: a governance perspective on defining the compatibility criteria, and a systems engineering case study on implementing them.</p> <ol> <li><strong>The Standard:</strong> We present the findings from the <a href="https://2025.pgconf.eu/community-events/establishing-the-postgresql-standard-whats-postgres-compatible/">"Establishing the PostgreSQL Standard"</a> working group held at PGConf.EU 2025. This progress report details the community's consensus on the hard requirements needed to fix the "wild west" of marketing claims, including:<ul> <li>Core SQL: Defining the non-negotiable functions, types, and PL/pgSQL.</li> <li>Protocol: Why wire compatibility is insufficient without consistent transactional and <code>pg_catalog</code> behaviour.</li> <li>Ecosystem: The critical requirements for integration with logical replication and tools like Patroni.</li> </ul> </li> <li><strong>The Implementation:</strong> Maintaining compatibility with MySQL/MariaDB in <a href="https://github.com/pingcap/tidb">TiDB</a>, a distributed database engine, is far more complex than matching syntax for an evolving SQL dialect:<ul> <li>We explore the architectural friction of making TiDB speak the MySQL wire protocol and support the MySQL syntax.</li> <li>We cover compatibility with the MySQL binary log based replication.</li> </ul> </li> </ol>