Great Expectations vs pgroll

Great Expectations (GX) is a framework for defining data tests and checking whether data meets their criteria. GX Core is a Python library for building and running data-validation workflows, and it requires Python versions 3.10 through 3.13. GX Cloud provides a web interface for data teams, including technical and nontechnical stakeholders, and runs tests in the environment where connected data resides using read-only connections. Data Docs turns Expectations, validation results, and related metadata into static web pages. GX lists data-source integrations including Databricks, BigQuery, Pandas, PostgreSQL, Snowflake, Spark, Redshift, and cloud storage services. Notification integrations include Slack, Email, PagerDuty, OpsGenie, and Microsoft Teams; orchestration integrations include Apache Airflow, Dagster, and Prefect. Custom rules can be written with SQL in GX Cloud or through GX Core. The Developer plan costs nothing and covers up to five data assets under test per month and three users, with unlimited rows per asset. Team and Enterprise have custom data-asset limits and no listed prices.

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.