---
title: "The cost of a JOIN, plus some new Postgres releases"
publication: "Postgres Weekly"
issue: 269
published_at: "2018-08-15"
canonical_url: "https://postgresweekly.com/issues/269"
---

The latest Postgres news, articles, tools, and projects.       

#269 — August 15, 2018 

[Read on the Web](https://postgresweekly.com/issues/269)   

Postgres Weekly 

[![\](https://res.cloudinary.com/cpress/image/upload/w_1280,e_sharpen:60/zmziuxgnm0qzinm9eq26.jpg)](https://www.brianlikespostgres.com/)  

[The Cost of a JOIN](https://www.brianlikespostgres.com/) — A ‘join’ is the combination of two sets of data (i.e. columns from two tables) and a _very_ frequently performed operation in SQL queries - but how _expensive_ are they? This post takes a practical look at what affects their performance in Postgres, and triggered quite a bit of [discussion on Hacker News.](https://news.ycombinator.com/item?id=17762067) 

Brian Likes Postgres   

[Lots of Postgres Releases (10.5, 9.6.10, 11 Beta 3, and More)](https://www.postgresql.org/about/news/1878/) — Two types of release here. Firstly, 10.5, 9.6.10, 9.5.14, 9.4.19 and 9.3.24 have been released to fix some bugs and two security vulnerabilities. Second, 11 beta 3 is out fixing bugs found in beta 2. 

PostgreSQL Global Development Group   [![\](https://copm.s3.amazonaws.com/e4ed43da.png)](http://www.2qpgconf.com) 

[2ndQuadrant PostgreSQL Conference 2018 - December 4 & 5](http://www.2qpgconf.com) — Join us in Chicago to learn more about recent achievements & exciting future developments in PostgreSQL. On Dec. 4 you can participate in hands on training with experts covering: multi-master replication, performance tuning, & PostgreSQL security. 

2ndQuadrant PostgreSQL Events sponsor   

[Fun with SQL: Common Table Expressions for More Readable Queries](https://www.citusdata.com/blog/2018/08/09/fun-with-sql-common-table-expressions/) — Common table expressions are essentially views that exist within a given transaction block. They’re a powerful construct that allow you to build more readable queries with better separation of logic. 

Craig Kerstiens   

[How to Convert a Postgres User to a Role](https://dan.langille.org/2018/08/09/postgresql-convert-a-user-to-a-role/) 

Dan Langille   

[Tuning Autovacuum in Postgres and Autovacuum Internals](https://www.percona.com/blog/2018/08/10/tuning-autovacuum-in-postgresql-and-autovacuum-internals/) 

Avinash Vallarapu   

[A Quick Example of a Postgres 'Rule'](https://fluca1978.github.io/2018/08/13/PostgreSQL-pgsettings-rules.html) 

Luca Ferrari   

[Top Resources for Postgres Perf Monitoring and Auditing](https://severalnines.com/blog/performance-monitoring-auditing-postgresql-top-resources) — A collection of links to posts about Postgres performance and tools. 

Severalnines   

[A Forthcoming PostgreSQL 12 Feature: Allow Multi-Inserts During COPY into a Partitioned Table](https://www.depesz.com/2018/08/13/waiting-for-postgresql-12-allow-multi-inserts-during-copy-into-a-partitioned-table/) 

depesz   

[Webinar Aug 21: Performance Monitoring for PostgreSQL - Sign Up Today](https://severalnines.com/resources/webinars/introduction-performance-monitoring-postgresql?utm_campaign=Database_Monitoring_AUG_2018&utm_content=pg_webinar&utm_medium=Paid_Search&utm_source=banner) 

Severalnines sponsor   

[Condenser: A Database Subsetting Tool for Postgres](https://github.com/TonicAI/condenser) — _“Subsetting a database means to take a subset of its rows, across multiple tables, while still maintaining all of the constraints of the original database.”_ 

Tonic   

[PgBouncer 1.9.0 Released: The Lightweight Connection Pooler](https://pgbouncer.github.io/2018/08/pgbouncer-1-9-0) 

PgBouncer   

[PostGIS 2.5.0 Beta 2 Released](http://postgis.net/2018/08/11/postgis-2.5.0beta2/) — Designed to be used with Postgres 11 beta 3 which was just released. 

PostGIS Developers  

Events  

[PostgresOpen 2018 Conference Schedule Released](https://www.postgresql.org/about/news/1877/) — **September 5-7 (San Francisco, CA)**   

[PostgreSQL Day 2018](https://pdx.postgresql.us/pdxpgday2018) — **September 10 (Portland, Oregon)** A day of presentations about PostgreSQL.    

[FOSDEM PGDay 2019](https://2019.fosdempgday.org/) — **February 1 2019 (Brussels, Belgium)** An extension to the regular PostgreSQL activities at FOSDEM.         

Curated by [Cooperpress](https://cooperpress.com/) and [Craig Kerstiens](https://twitter.com/craigkerstiens) 

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