Ask HN: What could a modern database do that PostgreSQL and MySQL can't
1. High performance read&#x2F;write of Scylla&#x2F;Cassandra with high availability[1]. It has some limitations for OLTP workloads and require careful planning. Postgres without Citus is not really HA and even then companies would often invent custom sharding&#x2F;cluster management system.<p>2. Powerful graph query language like Cypher. It might not perform well in real life, but my personal experience left me amazed[2]. There is a number of issues with SQL that could be addressed[3], but current standard is way too much prevalent.<p>3. Zero impedance mismatch between database and application representation. In database like Smalltalk GemStone it is really seamless experience for developer to write database code and application code[4]. To some extent, MongoDB success can be attributed to this aspect.<p>4. Datomic temporal capabilities[5]. It is hard to maintain temporal tables in postgres. There are some use cases where you really want query in point of time. Strictly not an OLTP feature, but I can see this be usefully in many scenarios.<p><pre><code>  [1] https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=Fo1dPRqbF-Q
  [2] https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=pMjwgKqMzi8&amp;t=726s
  [3] https:&#x2F;&#x2F;www.edgedb.com&#x2F;blog&#x2F;we-can-do-better-than-sql
  [4] https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=EyBkLbNlzbM
  [5] https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=7lm3K8zVOdY
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Edited: independence -&gt; impedance