Is it possible to compare two databases with identical structure? Let say that I have two databases DB1 and DB2 and I want to check if there is a difference in data between them.

There are several tools out there:

(note that most of these tools can only compare structure, but not data)

Free Ones:

• pgquarrel: http://eulerto.github.io/pgquarrel (schema diff)
• apgdiff http://apgdiff.com/ (schema diff)
• Liquibase (Cross DBMS): http://www.liquibase.org (schema diff)
• pgAdmin https://www.pgadmin.org (schema diff in pgAdmin4)
• WbDataDiff (Cross DBMS): http://www.sql-workbench.net/manual/compare-commands.html#command-data-diff (data diff)
• WbSchemaDiff (Cross DBMS): http://www.sql-workbench.net/manual/compare-commands.html
• Migra https://migra.djrobstep.com/ (schema diff)

Commercial:

• DB Comparer: http://www.sqlmanager.net/en/products/postgresql/dbcomparer
• Aqua Data Studio: http://docs.aquafold.com/docs-diff-schema.html
• DB Solo: http://www.dbsolo.com/index.html (30 day trial)
• PostgresCompare: https://www.postgrescompare.com/ (14 day trial, compares schema and data)