pgroll vs SQLancer

pgroll is an open-source command-line tool for PostgreSQL schema migrations that keeps old and new schema versions available while applications move between them. Its expand/contract workflow lets clients choose a version through PostgreSQL's search_path. The project describes migrations as zero-downtime and says it applies changes without locking the database; it can also backfill columns automatically when needed. For breaking changes, pgroll builds virtual schemas from views over physical tables and uses triggers to carry writes between old and new columns. Active migrations can be rolled back to the previous schema version. It supports PostgreSQL 14 and later, including RDS and Aurora, and is available for Linux, macOS, and Windows or self-hosting. It can convert SQL generated by ORMs, with examples for Alembic, Django, and Drizzle, though manual data migrations and SQL consolidation may be needed. On PostgreSQL 14, its versioned views do not respect row-level security policies, which can make it a poor choice for RLS users on that version. The project is licensed under Apache License 2.0.

SQLancer automatically tests database management systems to find implementation bugs. It generates SQL statements and database states, then validates query behavior with test oracles including TLP, NoREC, PQS, DQP, CODDTest, and CERT. Targets include logic bugs, performance issues, unexpected internal errors, and crashes. The supported-databases list contains 21 implementations, including PostgreSQL, MySQL, SQLite, DuckDB, and ClickHouse, while the impact page reports evidence of use by 22 DBMS projects. SQLancer runs on Linux, macOS, and Windows and requires Java 11 or above plus Maven. Releases are available through GitHub, Maven Central, and DockerHub. DuckDB, H2, and SQLite can run as embedded systems with binaries included as JAR dependencies. Runs may continue indefinitely when no bugs appear, with options to stop after a selected bug count or timeout. It is free under the MIT License.