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More on MyRocks Performance for Bug #68079 Case
My previous post on MyRocks was intended to provide some background details for a couple of slides for my FOSDEM talk on profiling MySQL. The results and performance demonstrated by MyRocks vs InnoDB...
View ArticleFun with Bugs #48 - Group Replication Bugs and Missing Features as of MySQL...
It seems recent post on Group Replication by Vadim caused an interesting discussion on Facebook. I am NOT going to continue it here, but decided to present some facts, specifically, list of public bug...
View ArticleMySQL Support Engineer's Chronicles, Issue #5
A lot of time passed since my previous post in this series. I was busy with work, participating in FOSDEM, blogging about profilers and sharing various lists of MySQL bugs. But I do not plan to stop...
View ArticleFun with Bugs #49 - Applying PMP to MySQL
As you maybe noted, in several recent posts I've provided some additional details for slides used during my FOSDEM talk on profiling MySQL. The only part not covered yet is related to using Poor Man's...
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Testing MyRocks vs InnoDB Performance Using sysbench 1.x oltp_point_select.lua
It seems MyRocks is going to become a hot topic in April 2017. Previously (here and there) I tried to compare its performance and scalability vs InnoDB from MySQL 5.7.17 using test case from famous bug...
View ArticleFun with Bugs #50 - On Bugs Tagged as "missing manual"
Back in January 2014, some time after many nice people kindly asked me to shut up stop writing about MySQL bugs on Facebook several times per day, I decided to start reading the fine MySQL Manual more...
View ArticleFun with Bugs #51 - My Bug Reports that Oracle doesn't Want to Fix
This week I noticed (yet another) customer issue related to the output produced by mysqladmin debug command (or when mysqld process gets SIGHUP signal). I mean the output generated by the...
View ArticleMy First Steps with MariaDB 10.2 and RocksDB Storage Engine
Last year I started to explore MyRocks, that is, RocksDB used as a storage engine with MySQL. So far I had to use Facebook's MySQL 5.6 to do this. I could try to use some specific development branches...
View ArticleAccessing Oracle tables via MariaDB CONNECT engine and ODBC
In my previous working environment it was typical to consider MariaDB Server as just a set of "random" storage engines mixed together, sometimes for unclear reasons and with questionable extra value....
View ArticleFun with Bugs #52 - On Some Bugs Fixed in MySQL 5.7.18
I had not reviewed MySQL 5.7 release notes for quite a some time in this series. Last time I checked it was MySQL 5.7.15. So, as soon as I noted new release, 5.7.18, I decided to check the release...
View ArticleHow To Find What Thread Had Executed FTWRL
This week one of MariaDB Support customers asked how to find what thread had executed FLUSH TABLES WITH READ LOCK (FTWRL) and thus blocked all changes to data. I decided to list several ways to find...
View ArticleMySQL Support Engineer's Chronicles, Issue #6
Previous post in series was published almost 4 months ago, but I do not plan to end it. So, let me quickly discuss some of problems I worked on or was interested in so far in June, and provide some...
View ArticleMy First Steps with MariaDB ColumnStore
This is a "Howto" kind of post, and some speculations and historical references aside, it will show you how to build MariaDB ColumnStore (current version 1.0.9) from GitHub source, how to install and...
View ArticleMySQL Support Engineer's Chronicles, Issue #7
This week in Support was busy enough for me. Among other things I had to study all possible reasons (other than obvious query cache impact) for queries hanging in "query end" status and noted Bug...
View ArticleFun with Bugs #53 - On Some Percona Software Bugs I've Reported
So far in this series I had written only/mostly about MySQL server bugs. Does it mean that there are no unique or interesting bugs in other MySQL-related software or MySQL forks and projects that use...
View ArticleFun with Bugs #54 - On Some Bugs Fixed in MySQL 5.7.19
More than 3 months after 5.7.18 we' ve got MySQL 5.7.19 released recently. This is my quick review of the release notes with interesting fixed bug (reported in public) highlighted in the areas I am...
View ArticleWhy Thread May Hang in "Waiting for table level lock" State - Part I
Last time I had to use gdb to check what's going on in MySQL server and found something useful with it to share in the blog post it was April 2017, and I miss this kind of experience already. So, today...
View ArticleHow to Find Processlist Thread id in gdb
I was involved in a discussion on some complex MySQL-related problem where we had to study backtraces of all threads in gdb (produced by the thread apply all bt command if you ever forgets this) in a...
View ArticleHow to Find Values of Session Variables With gdb
Usually I make notes while working on customer issues, reading the Slack channels or even scrolling across my Facebook news feed. Some of them are of "ToDo" kind, and this week while watching how my...
View ArticleHow to Find Values of User Variables With gdb
In his comment to my announcement of the previous post, Shane Bester kindly suggested to consider pretty printing the information about user variables from gdb. I tried to do this tonight, after a long...
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