In this post, I’ll walk through a set of common misconceptions that drive teams to introduce new infrastructure when they don’t need to. All of these can be solved with vanilla PostgreSQL 18 using standard extensions available on RDS, with no special infrastructure and no distributed-systems cosplay.

The database can be used for many things people often miss:

• user roles (finance) for modularity. In particular, a proper role can be used for defining very precise interfaces on top of database objects
• domains can be defined as an application of the abtract data type to database management
• a table for transfers can be stored with a system-time temporal table
• account audits (store old versions for logs)
• transaction state machine with functions
• record size estimation
• Heap-Only Tuple to avoid write amplification when primary keys are aligned with immutable columns. It enables faster updates. See https://ebellani.github.io/blog/2026/all-you-need-is-postgresql/#introduction:~:text=Enabling%20HOT%20Updates%20for%20Transfers,-By
• excellent OLTP (quick read and write individual rows) with a primary key reflecting the access pattern
• view to reuse queries from multiple tables
• excellent OLAP: large volumes of data while allowing quick query response times: a finance.balance_ledger table stores a snapshot of both balances after every transaction.
• incremental maintenance via triggers
• correct isolation with alter role finance set default_transaction_isolation = 'serializable';. If a cyclic transaction is detected, then one of the transaction fails. The application must be prepared to retry aborted transactions, but the invariants are never violated.

bookmark: https://ebellani.github.io/blog/2026/all-you-need-is-postgresql/#introduction:~:text=On%20decoupling,-Views