Tag: Fosdem

Feed: Planet MySQL; Author: Jean-François Gagné; I am now in an airport, waiting for one of the four flights that will bring me to Percona Live Santa Clara 2018.  This is a good time to write some details about my tutorial on parallel replication.  But before talking about Percona Live, I will share thoughts on MySQL/MariaDB bugs that caught my attention in the last weeks/months (Valeriy: you clearly have an influence on me). MySQL/MariaDB bugs Bug#69223 (Give a warning on CREATE TABLE without PRIMARY KEY by Daniël van Eeden) was brought back to my attention by Daniël publishing an audit plugin for that ... Read More

Feed: Planet PostgreSQL. Last week, I was at Nordic PGDay 2018 and I had quite a few conversations about the tool that I wrote, namely pglupgrade, to automate PostgreSQL major version upgrades in a replication cluster setup. I was quite happy that it has been heard and some other people in different communities giving talks at meetups and other conferences about near-zero downtime upgrades using logical replication. Given that there is a talk that I gave at PGDAY’17 Russia, PGConf.EU 2017 in Warsaw and lastly at FOSDEM PGDay 2018 in Brussels, I thought it is better to create a blog post ... Read More

Feed: Planet MySQL; Author: Frederic Descamps; Prior to MySQL 8.0, MySQL was missing a very well know feature in other RDBMS: optimizer histograms. The Optimizer Team implemented this feature as more and more MySQL DBAs were requesting it. Definition But what are histograms ? For wikipedia, a histogram is an accurate representation of the distribution of numerical data. For RDBMS, a histogram is an approximation of the data distribution within a specific column. So in MySQL, histograms help the optimizer to find the most efficient Query Plan. Example To illustrate how histograms  influence the optimizer, I will use data from ... Read More

Feed: Planet MySQL; Author: Øystein Grøvlen; The slides and video from my FOSDEM presentation on histogram support in MySQL can now be downloaded.  Check it out if you want to learn more about how you can create histograms to improve query plans in MySQL 8.0.The presentation shows you how to create histograms over column values,  presents the types of histograms you can create, and discusses best practices for using histograms.Prior to MySQL 8.0, the query optimizer lacked statistics on columns that are not indexed.  With histograms the query optimizer will be able to make more accurate selectivity estimates for conditions ... Read More

Feed: Percona Database Performance Blog. Author: Colin Charles. Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community. I think the biggest news from Percona-land is that besides the tutorial grid, the schedule for day 1 and day 2 are live! Also notice the many “sub-themes”: a 101 track, using MySQL, MongoDB, cloud, MySQL database software, PostgreSQL, containers & automation, monitoring & ops, and misc. database stuff. Learn from 107 different experts (this number is likely to increase). So register now. This coming week, Peter Zaitsev, Tom Basil, and ... Read More

Feed: Planet MySQL; Author: Giuseppe Maxia; How it happened A few years ago I started thinking about refactoring MySQL-Sandbox. I got lots of ideas and a name for the project (dbdeployer) but went no further. The initial idea (this was 2013!) was to rewrite the project in Ruby: I had been using Ruby at work and it looked like a decent replacement for Perl. My main problem was the difficulty of installation in an uncontrolled environment. If you have control over your environment (it's your laptop or you are in charge of the server configuration via Puppet or similar) then ... Read More

Feed: Planet MySQL; Author: Shlomi Noach; I was very pleased when Giuseppe Maxia (aka datacharmer) unveiled dbdeployer in his talk at pre-FOSDEM MySQL day. The announcement came just at the right time. I wish to briefly describe how we use dbdeployer (work in progress). The case for gh-ost A user opened an issue on gh-ost, and the user was using MySQL 5.5. gh-ost is being tested on 5.7 where the problem does not reproduce. A discussion with Gillian Gunson raised the concern of not testing on all versions. Can we run gh-ost tests for all MySQL/Percona/MariaDB versions? Should we? How ... Read More

Feed: Planet MySQL; Author: Jaime Crespo; I am happy that the MySQL team is, during the last years, blogging about each major feature that MySQL Server is getting; for example, the series on Recursive Common Table Expressions. Being extremely busy myself, I appreciate taking the time to share details with the advantage of being an insider point of view. However, first party guides and examples can be seen at times as not terrible useful at first- as normally they are done with synthetic, artificial examples and not real-life ones. I want to share with you 2 examples of how 2 ... Read More

Feed: Neo4j Graph Database Platform. Author: Mark Needham. Welcome to this week in Neo4j where we round up what’s been happening in the world of graph databases in the last 7 days. This week we have a sandbox to play around with NBC’s Russian Twitter Trolls dataset, modelling Pentaho ETL jobs and flights with Neo4j, a Python Cypher Querybuilder, Spring Boot, and more. Featured Community Member: Gábor Szárnyas This week’s featured community member is Gábor Szárnyas, Research assistant at Hungarian Academy of Sciences. Gábor Szárnyas – This Week’s Featured Community Member Gábor has been part of the Neo4j community for ... Read More

Feed: Percona Database Performance Blog. Author: Lorraine Pocklington. Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community. In case you missed last week’s column, don’t forget to read the fairly lengthy FOSDEM MySQL & Friends DevRoom summary. From a Percona Live Santa Clara 2018 standpoint, beyond the tutorials getting picked and scheduled, the talks have also been picked and scheduled (so you were very likely getting acceptance emails from the Hubb.me system by Tuesday). The rejections have not gone out yet but will follow soon. I expect the ... Read More