---
title: "CouchDB 3.0, recursive SQL queries, and a jellyfish-inspired database"
publication: "DB Weekly"
issue: 293
published_at: "2020-02-28"
canonical_url: "https://dbweekly.com/issues/293"
---

Plus more database news, views, and links.       

#293 — February 28, 2020 

[Read on the Web](https://dbweekly.com/issues/293)   

Database Weekly  

It's a compact and _bijou_ issue this week as Cooperpress is in the middle of some organizational changes — back to full service next week! 😄    

[How to Write Complex Recursive SQL Queries](https://habr.com/en/company/postgrespro/blog/490228/) — The English isn’t perfect as this is a translation, but the author knows his stuff and you could learn something here. 

Egor Rogov   

[CouchDB 3.0 Now Available](https://blog.couchdb.org/2020/02/26/3-0/) — CouchDB is a mature, JSON-document oriented NoSQL database, and one of the earlier modern generation of databases to be called ‘NoSQL’. 3.0 is an interesting release designed to [path the way to a FoundationDB-powered version 4.0](https://blog.couchdb.org/2020/02/26/the-road-to-couchdb-3-0-prepare-for-4-0/), with a curious side effect being a drop in the default maximum document size from 4GB to 8MB. 

Jan Lehnardt   [![\](https://copm.s3.amazonaws.com/6321fbe0.png)](https://studio3t.com/academy/?utm_source=cooper&utm_medium=newsletter&utm_campaign=dbweeklyfeb28) 

[Learn the Basics of MongoDB in Just Two Hours](https://studio3t.com/academy/?utm_source=cooper&utm_medium=newsletter&utm_campaign=dbweeklyfeb28) — Missing out on MongoDB? Don’t wait - Join hundreds of new learners and register for this free course today. 

Studio 3T sponsor   

[A Guide to Running Elasticsearch in Production](https://facinating.tech/2020/02/22/in-depth-guide-to-running-elasticsearch-in-production/) — Elasticsearch is a popular, flexible, and high performance document database that provides search engine functionality. This post covers a lot of what’s worth knowing about keeping it running in production. 

Mattis Haase   

[The Jellyfish-Inspired Database Under AWS Block Storage](https://www.nextplatform.com/2020/02/18/the-jellyfish-inspired-database-under-aws-block-storage/) — _“If you want inspiration for a hyperscale, resilient distributed block storage service, apparently a jellyfish is a good place to start looking for architectural features.”_ A high level introduction to Physalia, a massively distributed database service that stores the metadata for Elastic Block Store. 

Timothy Prickett Morgan   

[YugabyteDB 2.1 Now GA: Scaling New Heights with Distributed SQL](https://blog.yugabyte.com/yugabytedb-2-1-is-ga-scaling-new-heights-with-distributed-sql/) — YugabyteDB is an open source, distributed SQL database focused on resilience and low query latency. The 2.1 release brings better performance (at quite a significant level over YugabyteDB 2.0), two data center (2DC) deployments, read replicas, security enhancements (including key rotation), and more. 

Sid Choudhury   

[Google Adds In-Memory BI Option to BigQuery](https://www.datanami.com/2020/02/26/google-adds-in-memory-bi-option-to-bigquery/) — Response times for interactive queries in Google BigQuery are about to get better thanks to a new in-memory BI option. 

Alex Woodie   

[How to Read an (Oracle) Execution Plan](https://blogs.oracle.com/oraclemagazine/how-to-read-an-execution-plan) — Learn to follow and understand the steps and processes in an SQL statement’s execution plan. 

Chris Saxon (Oracle)   

[Snel: SQL Native Execution for LLVM](https://arxiv.org/abs/2002.09449) — A paper looking into Snel, a relational database engine featuring LLVM-powered Just-In-Time (JIT) compilation of queries, columnar data representation and which is either dynamically linked into other systems or works as an SQLite extension (so essentially an embedded OLAP database — [DuckDB](https://www.duckdb.org/) is worth considering if you want something similar that’s already open sourced). 

Mottalli, Ajzenman and Sarraute   

[Google Adds In-Memory BI Option to BigQuery](https://www.datanami.com/2020/02/26/google-adds-in-memory-bi-option-to-bigquery/) — Response times for interactive queries in Google BigQuery are about to get better thanks to a new in-memory BI option. 

Alex Woodie     

**Quick bytes:** 

- SQL Server supports [emojis in identifiers.](https://twitter.com/jbogard/status/1232038785485037570) Fun! Oracle does too (and so should any database that supports Unicode in identifiers).          

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