What Database Compare Tools cover
Use the page that matches the two inputs you need to check. Parquet Diff compares local Parquet files, including their file details and records. SQL Schema Diff compares SQL DDL schemas written in MySQL, PostgreSQL, SQLite, or SQL Server syntax. Both comparisons run in the browser, with no upload of the source files.
Compare Parquet files without converting to CSV
Choose Parquet Diff for two local Parquet files. The comparison includes field names, physical types, logical types, repetition or nullability details, and row-group counts. These details let you inspect the file structure before you review record differences. Record comparison has three choices: key, row order, and row-multiset hash. Use key when the records have a field to match on. Use row order when position is part of the comparison. Use row-multiset hash when the rows should be treated as a multiset.
Compare SQL DDL schemas before a migration
Choose SQL Schema Diff for two SQL DDL schemas. It accepts MySQL, PostgreSQL, SQLite, and SQL Server syntax, then reports added, removed, and changed database objects. The change log covers tables, columns, keys, constraints, indexes, and views. SQL Schema Diff checks the schema definition. It does not compare table records. Use Parquet Diff when the inputs are Parquet files and the comparison concerns file details or records.
Typical database comparison jobs
- Compare two SQL DDL schemas and review added, removed, or changed tables, columns, keys, and constraints.
- Check Parquet field names, physical and logical types, repetition or nullability details, and row-group counts before reviewing records.
- Compare Parquet records by key, row order, or row-multiset hash when the matching rule changes the result you need to inspect.
- Review views and indexes alongside tables and columns in a SQL schema change log.
Choosing between the comparison tools
Open Parquet Diff when both inputs are Parquet files and you need file details or record comparison. Open SQL Schema Diff when both inputs are SQL DDL schemas and you need a list of added, removed, or changed database objects. The two tools use different input types, so a Parquet file belongs in Parquet Diff and a schema definition belongs in SQL Schema Diff. For a different database task, visit Database Tools. That page links to tools for running SQL on CSV or JSON and for other work with Parquet files.
Frequently asked questions
What can I compare with Database Compare Tools?
You can compare two local Parquet files with Parquet Diff or two SQL DDL schemas with SQL Schema Diff. Parquet Diff covers file details and records. SQL Schema Diff reports changes to tables, columns, keys, constraints, indexes, and views.
How do I compare two Parquet files?
Open Parquet Diff with the two local Parquet files. Review the field and row-group details, then compare records by key, row order, or row-multiset hash.
Does SQL Schema Diff support MySQL and PostgreSQL?
SQL Schema Diff accepts SQL DDL schemas in MySQL, PostgreSQL, SQLite, or SQL Server syntax. It produces a change log for schema objects, including tables, columns, keys, constraints, indexes, and views.
Are my database files uploaded when I compare them?
No. Database comparisons in this category run locally in your browser, with no upload of the source files.