4. Assuming PostgreSQL works like proprietary databases

You've spent years mastering Oracle or SQL Server, and PostgreSQL seems similar enough on the surface. But this assumption can be costly. Proprietary databases often force you into specific design patterns and workflows that don't translate well to PostgreSQL's architecture. When you apply these proprietary patterns to PostgreSQL, you miss opportunities to leverage its unique strengths, hitting unexpected performance walls and creating unnecessary complexity.

Breaking free from proprietary thinking is essential to fully realize PostgreSQL's advantages instead of forcing it to behave like the expensive systems you're leaving behind.

Consider this: Oracle DBAs rely on materialized views, and SQL Server uses clustered indexes, but PostgreSQL's query planner works differently. Forcing these proprietary patterns onto PostgreSQL creates performance issues as its MVCC model, indexing approach, sequence behavior, and dynamic execution planning require fundamentally different optimization strategies.