Every day at Percona Live 2017 brings something new and unusual – and on this particular day, we found out that MySQL makes toast.

A lot of people think that with MySQL and open source software, you can do anything. While many might view this metaphorically, Percona’s Alexander Rubin (Principal Consultant) takes this statement very seriously. He demonstrated on Tuesday at Percona Live that not only is possible to accomplish just about anything with MySQL, but MySQL makes toast!

Originally, Alexander took on this project to provide an open source fix for MySQL Bug#2 (MySQL Doesn’t Make Toast). After some effort, and some ingenuity, he provided a patch for the infamous bug.

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Thank you for attending my July 22 webinar titled “Advanced Query Tuning in MySQL 5.6 and 5.7” (my slides and a replay available here). As promised here is the list of questions and my answers (thank you for your great questions).

Q: Here is the explain example:

mysql> explain extended select id, site_id from test_index_id where site_id=1
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: test_index_id
         type: ref
possible_keys: key_site_id
          key: key_site_id
      key_len: 5
          ref: const
         rows: 1
     filtered: 100.00
        Extra: Using where; Using index

why is site_id a covered index for the query, given the fact that a) we are selecting “id”, b) key_site_id only …

About 2 weeks ago Oracle published the MySQL 5.7.7-labs-json version which includes a very interesting feature called “Generated columns” (also know as Virtual or Computed columns). MariaDB has a similar feature as well: Virtual (Computed) Columns.

The idea is very simple: if we store a column

`FlightDate` date

in our table we may want to filter or group by year(FlightDate), month(FlightDate) or even dayofweek(FlightDate). The “brute-force” approach: use the above Date and Time MySQL functions in the query; however it will prevent MySQL from using an index (see below). Generated columns will allow you to declare a “Virtual”, non-stored column …

MySQL introduced the Event Scheduler in version 5.1.6. The Event Scheduler is a MySQL-level “cron job”, which will run events inside MySQL. Up until now, this was not a very popular feature, however, it has gotten more popular since the adoption of Amazon RDS – as well as similar MySQL database as a service offerings where there is no OS level.

What is important to understand about the Event Scheduler is that it does not have any protection against multiple execution (neither does linux cron). Let’s imagine you have created an event that executes every 10 seconds, but the logic inside the event (i.e. queries or stored procedure call) can …

I will be presenting two webinars in August:

• Aug 6, 10 a.m. PDT: Advanced Query Tuning in MySQL 5.6 and Beyond
• Aug 13, 10 a.m. PDT:  Using Performance Schema to Monitor and Troubleshoot MySQL 5.6

This Wednesday’s webinar on advanced MySQL query tuning will be focused on tuning the “usual suspects”: queries with “Group By”, “Order By” and subqueries; those query types are usually perform bad in MySQL and add an additional load as MySQL may need to create a temporary table(s) or perform a filesort. New this year: I will talk more about new MySQL …

In my previous post about geo-spatial search in MySQL I described (along with other things) how to use geo-distance functions. In this post I will describe the geo-spatial distance functions in more details.

If you need to calculate an exact distance between 2 points on Earth in MySQL (very common for geo-enabled applications) you have at least 3 choices.

• Use stored function and implement haversine formula
• Use UDF (user defined function) for haversine (see below)
• In MySQL 5.6 you can use st_distance …

When you make a change to your MySQL configuration in production it would be great to know the impact (a “before and after” type of picture). Some changes are obvious. For many variables proper values can be determined beforehand, i.e. innodb_buffer_pool_size or innodb_log_file_size. However, there is 1 configuration variable which is much less obvious for many people working with MySQL: query_cache.

The idea of query cache is great, however, there are a lot of issues with MySQL query …

The new Percona Server 5.5.37-35.0 and Percona Server 5.6.17-65.0-56, announced yesterday (May 6), both include the open source version of the MySQL Audit Plugin. The MySQL Audit Plugin is used to log all queries or connections (“audit” MySQL usage). Until yesterday’s release, the MySQL Audit Plugin was only available in MySQL Enterprise.

EDIT:  Just to be clear, this implementation is alternative to the MySQL …

In my previous post I’ve showed some new MySQL 5.6 features which can be very helpful when creating geo-enabled applications. In this post I will show how we can obtain open-source GIS data, convert it to MySQL and use it in our GEO-enabled applications. I will also present at the upcoming Percona Live conference on this topic.

Data sources (US)

For the U.S. we may look at 2 major data sources:

1. ZIP codes with latitude, longitude and zip code boundaries (polygon). This can be downloaded from the U.S. Census website: …

I will be talking about Big Data with MySQL and Hadoop at MySQL Connect 2013 (Sept. 21-22) in San Francisco as well as at Percona University at Washington, DC (September 12, 2013). Apache Hadoop is a very popular Big Data solution and we can nowadays easily integrate it with MySQL. I will start with a brief introduction of Apache Hadoop and its components (HFDS, Map/Reduce, Hive, HBase/HCatalog, Flume, Scoop, etc). Next I will show 2 major Big Data scenarios:

• From file to Hadoop to MySQL. This is an example of “ELT” process: Extract data from external source; Load data into Hadoop; Transform data/Analyze data; Extract results to MySQL. It is similar to the original Data Warehouse ETL …