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Displaying posts with tag: 5.7 (reset)
On Importing InnoDB Tablespaces and Row Formats

Let me start with a short summary and then proceed with a long story, code snippets, hexdumps, links and awk functions converted from the source code of MariaDB server. This blog post can be summarized as follows:

  • One can find row_format used to create table explicitly in the .frm file (or the outputs of SHOW CREATE TABLE or SHOW TABLE STATUS). Internals manual may help to find out where is it stored and source code reading helps to find the way to interpret the values.
  • For InnoDB tables created without specifying the row_format explicitly neither logical backup nor .frm file itself contains the information about the row format used. There are 4 of them (Redundant, Compact, Dynamic and Compressed). The one used implicitly is defined by current value of the …
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Fun with Bugs #85 - On MySQL Bug Reports I am Subscribed to, Part XX

We have a public holiday here today and it's raining outside for a third day in a row already, so I hardly have anything better to do than writing yet another review of public MySQL bug reports that I've subscribed to recently.

Not sure if these reviews are really considered useful by anyone but few of my readers, but I am still going to try in a hope to end up with some useful conclusions. Last time I've stopped on Bug #94903, so let me continue with the next bug in my list:

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Fun with Bugs #84 - On Some Public Bugs Fixed in MySQL 5.7.26

Oracle released minor MySQL Server versions in all supported branches on April 25, 2019. MySQL 5.7.26 is just one of them, but recently I prefer to ignore MySQL 8 releases (after checking that I can build them from source code at least somewhere, even if it takes 18G+ of disk space and that they work in basic tests), as there are more chances for MySQL 5.7 bug fixes to affect me (and customers I care about) directly.

So, in this yet another boring blog post (that would never be a reason for any award) I plan to concentrate …

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Fun with Bugs #83 - On MySQL Bug Reports I am Subscribed to, Part XIX

I have not much yet to say on a popular topic of upgrading everything to MySQL 8, so let me just continue reviewing public MySQL bug reports that I've subscribed to recently. After my previous post at least one bug, Bug #94747, got enough comments and clarifications (up to specific commit that introduced this regression pointed out by Daniel Black!) to have it re-classified and verified as InnoDB code bug. So, I see good reasons to continue attracting wide public attention …

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MySQL InnoDB Cluster – how to manage a split-brain situation

Everywhere I go to present MySQL InnoDB Cluster, during the demo of creating a cluster, many people doesn’t understand why when I’ve 2 members, my cluster is not yet tolerant to any failure.

Indeed when you create a MySQL InnoDB Cluster, as soon as you have added your second instance, you can see in the status:

    "status": "OK_NO_TOLERANCE",      
"statusText": "Cluster is NOT tolerant to any failures.",


Why is that ? It’s because, to be part of primary partition (the partition that holds the service, the one having a Primary-Master in Single Primary Mode, the default mode), your partition must reach the majority of nodes (quorum). In MySQL InnoDB Cluster (and many other cluster solutions), to achieve quorum, the amount of members in a partition must be > (bigger) than 50%.

So when we have 2 nodes, if there is a network issue between …

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dbdeployer cookbook - usability by example

When I designed dbdeployer, I wanted to eliminate most of the issues that the old MySQL-Sandbox had:

  • dependencies during installation
  • mistaken tarballs
  • clarity of syntax
  • features (un)awareness.

Dependencies during installation did go away right from the start, as the dbdeployer executable is ready to be used without additional components. The only dependency is to have a host that can run MySQL. There is little dbdeployer can do about detecting whether or not your system can run MySQL. It depends on which version and flavor of MySQL you are running. It should not be a big deal as I assume that anyone in need of dbdeployer has already the necessary knowledge about MySQL …

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Migrate from MariaDB to MySQL on CentOS

On this article, I will show you how to migrate your wordpress database from the MariaDB on CentOS to the real MySQL.

Why migrating to MySQL 8.0 ?

MySQL 8.0 brings a lot of new features. These features make MySQL database much more secure (like new authentication, secure password policies and management, …) and fault tolerant (new data dictionary), more powerful (new redo log design, less contention, extreme scale out of InnoDB, …), better operation management (SQL Roles, instant add columns), many (but really many!) replication enhancements and native group replication… and finally many cool stuff like the new Document Store, the new MySQL Shell and MySQL InnoDB Cluster that you should already know if you follow this …

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Fun with Bugs #81 - On MySQL Bug Reports I am Subscribed to, Part XVII

Two weeks passed since my previous review of public MySQL bug reports I consider interesting enough to subscribe to them. Over this period I picked up a dozen or so new public bug reports that I'd like to briefly review today.

Here is my recent subscriptions list, starting from the oldest bug reports:

  • Bug #94431 - "Can't upgrade from 5.7 to 8.0 if any database have a hyphen in their name". It seems one actually needs a database like that created in MySQL 5.6 with at least one InnoDB table having FULLTEXT index to hit the problem. Great finding by Phil Murray. Note that after several unsuccessful attempts by others the bug was eventually reproduced and verified by …
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Fun with Bugs #80 - On MySQL Bug Reports I am Subscribed to, Part XVI

Today I'd like to continue my review of public MySQL bug reports with a list of some bugs I've subscribed to over last 3 weeks. It's already long enough and includes nice cases to check and share. Note that I usually subscribe to a bug either because it directly affects me or customers I work with, or I consider it technically interesting (so I mostly care about InnoDB, replication, partitioning and optimizer bugs), or it's a "metabug" - a problem in the way public bug report is handled by Oracle engineers. These are my interests related to MySQL bugs.

As usual, I start with the oldest bugs and try to mention bug reporters by name with links to their other reports whenever this may give something useful to a reader. I try …

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Fun with Bugs #79 - On MySQL Bug Reports I am Subscribed to, Part XV

More than 3 weeks passed since my previous review of public MySQL bug reports I am subscribed to, so it's time to present some of the bugs I've considered interesting in January, 2019.

As usual, I'll review them starting from the oldest and try to summarize my feelings about these bugs at the end of this post. Here they are:

  • Bug #93806 - "Document error about ON DUPLICATE KEY UPDATE". Years pass, but fine MySQL manual still does not explain some cases of InnoDB locking properly. Xiaobin Lin found yet another case that it does not explain properly. Or, maybe, the manual is correct and the problem in …
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