Editing Distributed database (section)

== Architecture ==
There are 3 main architecture types for distributed databases:

* [[Shared-memory architecture|Shared-memory]]: very rarely used<ref name=":0">{{Cite web |last=Garrod |first=Charlie |date=2023 |title=Lecture #21: Introduction to Distributed Databases |url=https://15445.courses.cs.cmu.edu/spring2023/notes/21-distributed.pdf |access-date=2023-03-12 |website=Carnegie Mellon University - School of Computer Science}}</ref>
* [[Shared-disk architecture|Shared-disk]]
* [[Shared-nothing architecture|Shared-nothing]]

In the shared-memory and shared-disk architectures, the data is not [[Partition (database)|partitioned]], but it has to be in a shared-nothing architecture.

Shared-disk architecture is more common for [[Cloud database|cloud databases]] than for on-premise.<ref name=":0" />

Historically, shared-nothing was the first architecture to be implemented on the cloud, before the advent of shared cloud storage made shared-disk possible.

In practice, different layers of the database can have different architectures. It is now common to have a compute layer with a shared nothing architecture, and a storage layer with a shared disk architecture. This is for instance the case of [[Snowflake Inc.|Snowflake]]<ref>{{Cite web |last=Kaushik |first=Arun |date=2020-02-14 |title=What Makes Snowflake So Powerful — It's the Hybrid of Shared Disk and Shared Nothing Architecture |url=https://medium.com/@a.kaushik5587/what-makes-snowflake-so-powerful-its-the-hybrid-of-shared-disk-and-shared-nothing-architecture-5b4fa8f039fa |access-date=2024-03-12 |website=Medium |language=en}}</ref> and [[Amazon Aurora|AWS Aurora]].<ref>{{Cite web |last1=Brahmadesam |first1=Murali |last2=Ternstrom |first2=Tobias |date=2019 |title=Amazon Aurora storage demystified: How it all works |url=https://d1.awsstatic.com/events/reinvent/2019/REPEAT_Amazon_Aurora_storage_demystified_How_it_all_works_DAT309-R.pdf |access-date=2024-03-12}}</ref>

=== List of shared-nothing databases ===

* [[IBM Db2]]
* [[Greenplum]]
* [[Netezza]]
* [[Teradata]]
* [[TiDB]]
* [[Vertica]]

=== List of shared-disk databases ===

* [[Amazon Aurora|AWS Aurora]]
* Neon
* [[Snowflake Inc.|Snowflake]]