The Nordic Talks: Alter your Schema and Recover if Broken

The ULB will host our next Meetup, on March 5. We are very happy to have two
speakers that will present at Nordic PgDay, so we are brining part of this event
to our local meetup. Pizza and drinks will be offered by OVHcloud.

• "Database schema management for lazybones: from chaos to heaven". Julien Riou, OVHcloud.
  https://www.postgresql.eu/events/nordicpgday2020/schedule/session/2971-database-schema-management-for-lazybones-from-chaos-to-heaven/

• "Point-in-time Recovery, target 2020". Stefan Fercot, Dalibo.
  https://www.postgresql.eu/events/nordicpgday2020/schedule/session/2945-point-in-time-recovery-target-2020/

The location will be the same as FOSDEM, just make sure to find the right building and room. Here are the details:

Salle des professeurs, S UA4 118
(Solbosch campus, same as FOSDEM, building U, door A, level 4, room 118).

Here is the campus map:
https://www.ulb.be/en/solbosch/campus-map

The address is Avenue Paul Héger 1000 Bruxelles.

By public transport, the nearest stop is: ULB, lines 71(bus), 25, 8 (tram).

Here are the descriptions of the talks and the speakers

• Database schema management for lazybones: from chaos to heaven

Performing schema changes on a live system is challenging because it often involves high level of locks leading to downtime. It becomes harder and harder when the number of databases to manage raise continuously. At OVHcloud, a major cloud computing provider in Europe, we used to manage such changes approximately. With our startup mindset, we used to yell "Who can ALTER my database?" and hope for someone sitting next to you to answer. Database engineers were used to copy paste bunch of SQL statements on production databases directly. What happens if a bad character is inserted? What if there is no transaction in the script? What if you run the migration on the wrong database? It works, sometimes. Lots of tasks are boring. This one was on top of our list. In this talk, you will discover our feedback on how we have reduced efforts, time and human errors by automating databases schema migrations using git, code reviews, CI/CD, migration tools and Ansible at the OVHcloud scale.

** Julien Riou
Company: OVHcloud

DBA since 2012 in the web hosting world. Open source DBMS specialist (PostgreSQL, MySQL). Currently Tech Lead in the databases team at OVHcloud, a major Cloud Computing provider in Europe.

• Point-in-time Recovery, target 2020

Your pg_dump takes forever? You want to save your data more frequently? Have you ever heard of Point-in-time recovery?

In his talk, we'll introduce what is called Point-in-time Recovery (aka "live backup").

We'll see how to achieve it step-by-step if you want to do manually: * archive_command / pg_recievewal; * pg_basebackup; * exclusive backup; * non-exclusive backup; * restore.

PostgreSQL 12 brought a significant change in this area with the removal of the recovery configuration file. We'll see more precisely the impact of this change.

We'll then mention some interesting backup (and restore) tools and give some key points to compare them (documentation, parallel execution, compression, incremental backups,...).

** Stefan Fercot
Company: Dalibo
Twitter: @pgstef

PostgreSQL Database and Linux System Administrator since 2010.

Worked on a large number of servers in the Belgian health-care area, deploying software upgrades, handling database backups and keeping systems up-and-running.

Working for Dalibo as a DBA since July 2017. Enjoying contributing to the community since then.

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Thanks to Mahmoud Sakr from ULB for hosting this event