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Displaying posts with tag: regression (reset)
Fun with Bugs #43 - Bugs Fixed in MySQL 5.7.13

For some reason I do not see numerous public announcements about recent MySQL 5.7.13 release, even though it happened a couple of days ago formally. Maybe that's because we do not have any really "big" new features in this release (new ->> operator for introduced though for those who, unlike me, care about JSON). Still there are many fixes for bugs previously reported by Community (or Oracle engineers, but still in public bugs database), and I'd like to discuss some of them.

Let me start with the bug that was NOT fixed though, Bug #81093, "mysqld_multi not included in mysql-community-server package", reported by Georgi Iovchev and …

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Fun with Bugs #42 - Bugs Fixed in MySQL 5.7.12

MySQL 5.7.12 was released more than 2 weeks ago. New features introduced there in a form of "rapid plugins" are widely discussed, but I am more interested in bugs reported by MySQL Community users that are fixed there. Unfortunately I do not see MySQL Community Release Notes by Morgan (like this) for quite a some time, so I have to continue describing key bug fixes and name people who reported and verified bugs in my "Fun with Bugs" series.

As usual, let's start with InnoDB bugs fixed:

  • Bug #80070 - "allocated_size and file_size differ if create general tablespace outside datadir". It was reported by my former colleague from Percona …
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Fun with Bugs #41 - Bugs Fixed in MySQL 5.7.11

I've just noted that Oracle had released new versions of MySQL on February 5, 2016 formally, so while these days I am mostly thinking about the ways to do support properly, remembering my colleagues and trying to understand some of RocksDB internals, it's time to postpone all these and write about bugs again. This time about some of the public bug reports from MySQL Community and Oracle engineers that were fixed by Oracle in MySQL 5.7.11.

As usual, I'll try to mention who had reported a bug and who verified it, as I think that names matter in MySQL world. I'll concentrate mostly on InnoDB, replication and optimizer bug reports, trying to highlight regressions clearly.

As usual, I prefer to start with InnoDB bugs:

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MySQL Support People - Percona Support

I planned to continue this series of posts with the one about MySQL Support engineers who joined us in Oracle while I was working there, but based on recent events in my life I'd prefer to postpone it and move directly to the team I worked for during last 3+ years, Percona Support Team.

Disclamer: In the list below I still try to pay attention to public contribution by each of engineers mentioned to MySQL Community, mostly in a form of bug reports. This is not the only way they contributed, but I have to stick to this format in current series of posts. I also base my comments mostly on my memory and quick search of public sources of information, so I may be mistaking about the roles, time periods and other details. Please, inform me if you think there is something to fix.

So, here is the list of my former colleagues who formed the best MySQL Support team in the industry in 2013-2015 while working with me in …

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Fun with Bugs #39 - Known Bugs in MySQL 5.7.9 GA

These days everybody is excited with recent announcement of MySQL 5.7.9 GA release. If you are not aware of this event yet (I've noted it from numerous posts even during my short vacation), wait for the Oracle Open World 2015 to begin tomorrow to announce it even wider and louder!

I already have 5.7.9 built from source, up and running, so it's time to check what else we can expect from this new GA release besides new great features (this is a topic for a separate post or two) and usual excitement. Yes, I mean known, verified bugs in MySQL 5.7.9.

Let me start with a quick summary and then present the details. So, even though MySQL Community tried hard to check 5.7.x at early stages and report bugs to Oracle, MySQL 5.7.9 GA has a number of known …

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Fun with Bugs #38 - Regression Bugs in MySQL 5.6

I often have to reply to questions related to upgrade from, say, MySQL 5.5.x to latest MySQL (or Percona) Server 5.6.x (5.6.27 for MySQL and 5.6.26 for Percona at the moment). One of them is sometimes about "any known bugs" that may affect a user after upgrade.

One may assume that now, 2 years and 8 months after the first GA release of MySQL 5.6.10, there should be very few bugs (we call them regression bugs) of a kind that is interesting for the user planning upgrade from 5.5.x. I checked yesterday and found out it's not the case actually. It took me half an hour to end up with the list of more than 20 regression bugs that are still "Verified", so may affect even the latest recent release, 5.6.27. I had not checked them one by one on 5.6.27 yet (it will take more than half an hour probably), but still would like to …

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Testing the Fastest Way to Import a Table into MySQL (and some interesting 5.7 performance results)

As I mentioned on my last post, where I compared the default configurations options in 5.6 and 5.7, I have been doing some testing for a particular load in several versions of MySQL. What I have been checking is different ways to load a CSV file (the same file I used for testing the compression tools) into MySQL. For those seasoned MySQL DBAs and programmers, you probably know the answer, so you can jump over to my 5.6 versus 5.7 results. However, the first part of this post is dedicated for developers and MySQL beginners that want to know the answer to the title question, in a step-by-step fashion. I must say I also learned something, as I under- and over-estimated some of the effects of certain …

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MySQL 5.5.40 Overview and Highlights

MySQL 5.5.40 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.5.html

This release, similar to the last 5.5 release, is mostly uneventful.

There were 0 “Functionality Added or Changed” bugs this time, and 18 bugs overall fixed.

Out of the 18 bugs, most seemed rather minor or obscure, but there are 3 I think are worth noting (all 3 are InnoDB-related, regressions, and serious if you encounter them, so best to be aware of them):

  • InnoDB: An ALTER TABLE … ADD FOREIGN KEY operation could cause a serious error. (Bug #19471516, Bug #73650)
  • InnoDB: With a transaction isolation level less than or equal to READ COMMITTED, gap locks …
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Fun with Bugs #28 - regression bugs in MySQL 5.6

2013 was a great year for MySQL Community. New MySQL 5.6 GA release with its increased throughput, scalability and new features as well as more interaction and cooperation with MySQL Community from Oracle side brought us a lot of new perspectives and good feelings over the year.

Unfortunately new MySQL 5.6 GA release also reminded about old and well known problem with new MySQL versions. They all introduce new regression bugs. MySQL 5.6 had not become an exception.

Note that according to good old tradition (that I hope will be followed in 2014) bugs that demonstrate a regression (make some feature that previously worked stop functioning as intended in a new release) are marked with "regression" tag at http://bugs.mysql.com. So, it's easy to find them, and …

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Fun with Bugs #22 - Some Bug Reports You Should Not Miss

Yet another user installed MySQL 5.5.32 yesterday and got a system that can not start... It's really easy to help in this case - just downgrade back to 5.5.31 or upgrade to 5.5.33 if you can. Why problem happened during upgrade? Because of a regression bug #69623.

This case that was easily solved during a quick chat reminded me about the problem of bugs in production. Nobody expects any sane DBA to review every new bug report, but some of them should not be missed, at least when upgrading to any newer version. Regression bugs (I see 15 here reported for …

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