Whenever I stick my head into the MySQL storage engine API, I’m reminded of a MySQL User Conference from several years ago now.

Specifically, I’m reminded of a slide from an early talk at the MySQL User Conference by Paul McCullagh describing developing PBXT. For “How to write a Storage Engine for MySQL”, it went something like this:

Develop basic INSERT (write_row) support – INSERT INTO t1 VALUES (42)

Develop full table scan (rnd_init, rnd_next, rnd_end)  - SELECT * from t1

If you’re sane, stop here.

A lot of people stop at step 3. It’s a really good place to stop too. It avoids most of the tricky parts that are unexpected, undocumented and unlogical (yes, I’m inventing words here).

Just went through all my PHP testing against a fresh instance of Oracle with Zend Server Community Edition 6, and found these warnings, guess that’s pretty clean for the Oracle part of the installation. I didn’t notice it before because generally I do most of my PHP development against a MySQL database. I should have been configuring the php.ini file routinely.

Warning: oci_set_client_info(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone. in C:\Program Files (x86)\Zend\Apache2\htdocs\Oracle\Db.php on line 47
Warning:

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A new release for mycheckpoint: lightweight, SQL oriented MySQL monitoring solution.

If you're unfamiliar with mycheckpoint, well, the one minute sales pitch is: it's a free and open source monitoring tool for MySQL, which is extremely easy to install and execute, and which includes custom queries, alerts (via emails), and out of the box HTTP server and

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There’s a big difference in how plugins are treated in MySQL and how they are treated in Drizzle. The MySQL way has been to create a C API in front of the C++-like (I call it C- as it manages to take the worst of both worlds) internal “API”. The Drizzle way is to have plugins be first class citizens and use exactly the same API as if they were inside the server.

This means that MySQL attempts to maintain API stability. This isn’t something worth trying for. Any plugin that isn’t trivial quickly surpasses what is exposed via the C API and has to work around it, or, it’s a storage engine and instead you have this horrible mash of C and C++. The byproduct of this is that no core server features are being re-implemented as plugins. This means

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Lately there have been a lot of organisations trying to hire a devops engineer.
I myselve have been asked to fill in devops roles ..

There's a number of issues with that.

The biggest problem is that I always have to ask what exactly the organisation is looking for.

So you want a devops engineer with experience in Linux, MongoDB, MySQL and Java , does that mean you want a Java developer who is familiar with MySQL and Linux and breaths a devops Culture.
Or a Linux expert who understands Java developers and knows how to tune Mongo and MySQL ?

It's absolutely unclear what you want when you are hiring "A devops engineer"

The second problem is that you are trying to hire people who are knowledgeable about devops,

Yet a lot of those people know that you can't do devops on your own , devops is not a jobtitle. devops is not a new devops

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I had reason to look into the extended secondary index code in MariaDB and MySQL recently, and there was one bit that I really didn’t like.

MariaDB:

share->set_use_ext_keys_flag(legacy_db_type == DB_TYPE_INNODB);

MySQL:

use_extended_sk= (legacy_db_type == DB_TYPE_INNODB);

In case you were wondering what “legacy_db_type” actually does, let me tell you: it’s not legacy at all, it’s kind of key to how the whole “metadata” system in MySQL works. For example, to drop a table, this magic number is used to work out what storage engine to call to drop the table.

Now, these code snippets

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A while back one of my foreign keys started causing trouble. The problem was that some parent rows had tens of thousand of child rows, and the foreign key was defined with CASCADE DELETE enabled. When we deleted one of those parent rows on a master database, it took several seconds to execute the delete because of the cascade. This led to latency for the end user, and also led to replication delays.

The immediate solution was make the application tolerant of orphaned rows in the child table and to drop the explicit foreign key constraint.

I didn't really want to leave those orphaned rows hanging around in the child table, so I decided to implement an asynchronous process to delete the orphaned rows on a scheduled basis. Read on for a description of that process.

Using the

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It is finally here.  After three years of development, the new version of Shard-Query is finally available for broad testing.

This new version of Shard-Query is vastly improved over previous versions in many ways.  This is in large part due to the fact that the previous version of Shard-Query (version 1.1) entered into production at a large company.  Their feedback during implementation was invaluable in building the new Shard-Query features.   The great thing is that this means that many of the new 2.0 features have already been tested in at least one production environment.

This post is intended to highlight the new features in Shard-Query 2.0.  I will be making posts about individual features as well as posting benchmark results.

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Most serious users of MySQL have moved their tables to InnoDB years ago.  For those who haven't, let's discuss why InnoDB is a more scalable solution than MyISAM. MyISAM was designed to be very fast for read queries.  It does not handle higher loads of writes very well.  It also suffers a more serious flaw: it isn't crash-safe.  In other words, you better have frequent backups. MyISAM tables

I was sincerely affected by this last MySQL post and this other very long post from Jeremy Cole.
Yes, these two guys are MySQL rock stars and they are really impressives, their involvement in the MySQL community is utter!

I don’t want to write a long long speech about my simple life…
I just want to clarify why I do what I do.

Many people have asked or wondered without asking why I do what I do
(Jeremy Cole - 2013)

A few years ago Ashley Unitt asked me what I was most proud of, and now, I can make a complete answer. I’m very proud to take part of a community, MySQL has transformed my job into a passion and an incredible desire to share this

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I've already shared my presentation few hours before I made it during PLMCE 2013, back on April 24. Let's just have it here for the reference: http://www.slideshare.net/ValeriyKravchuk/mysql-56experiencesbugssolutions50mins.

During the upcoming weeks I plan to explain every slide in more details (as 50 minutes were not enough for this) here and check status of all the active bugs mentioned in it. I'll also check new bugs for each major feature mentioned (if any). So, stay tuned...

I was playing around with MySQL 5.7 this weekend and before having read the changelog, I managed to spot these two little gems.

Duplicate Indexes

“The server now issues a warning if an index is created that duplicates an existing index, or an error in strict SQL mode.” Bug #37520

Example Testcase:

mysql> SHOW CREATE TABLE city\G
*************************** 1. row ***************************
       Table: city
Create Table: CREATE TABLE `city` (
  `ID` int(11) NOT NULL AUTO_INCREMENT,
  `Name` char(35) NOT NULL DEFAULT '',
  `CountryCode` char(3) NOT NULL DEFAULT '',
  `District` char(20) NOT NULL DEFAULT '',
  `Population` int(11) NOT NULL DEFAULT

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Everybody seems to be looking at and debating NoSQL these days, and so am I and I thought I'd say a few words about it. Which is not to say I haven't said stuff before, bit them I was mainly targeting specific attributes of many NoSQL solutions (like "eventual consistency" or, as you might call it, "instant inconsistency", What I was opposing is that "eventual consistency" has anything to do with just that, consistency. Rather, what this means is that at any point in time the system is inconsistent, and even if it might be consistent, you cannot rely on it being so. Which is fine, but don't call it consistency, call it inconsistency. Allowing a database to be somewhat inconsistent doesn't necessarily mean that it's something wrong with it).

All this said, what is going on here, why are we MySQL and MariaDB users seeing so many

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343 revisions after the 7.0 release follows the new 8.0 release of HeidiSQL now.

Get it from the download page.

Here are the most noticable changes:


- Available in 23 languages now. Thanks to all translators and Transifex hereby!
- Database tree: Introduce optional folders for tables, views, routines etc.
- Introduce session folders in session manager.
- Make routine editor work on MS SQL servers.
- Support search and replace in data and query results.
- Add support for microseconds in temporal datatypes of MariaDB 5.3+ and MySQL 5.6.
- Introduce a query history, available in the right side helpers box. Can be turned off.
- Implement grid export as PHP array.
- Host > Variables: Add "Global" column, and highlight values different to their session














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