Recent Posts by Mark Lewin

A really convenient feature in MySQL 8.0 is the ability to persist the values of global variables across server restarts, without writing them into an options file. This was developed primarily for the benefit of Cloud installations of MySQL, but is very handy for a DBA in on-premise installations too. To use this feature you need to have the SYSTEM_VARIABLES_ADMIN and PERSIST_RO_VARIABLES_ADMIN privileges. To demonstrate, we'll increase the value of the max_connections system...

A really convenient feature in MySQL 8.0 is the ability to persist the values of global variables across server restarts, without writing them into an options file. This was developed primarily for the benefit of Cloud installations of MySQL, but is very handy for a DBA in on-premise installations too. To use this feature you need to have the SYSTEM_VARIABLES_ADMIN and PERSIST_RO_VARIABLES_ADMIN privileges. To demonstrate, we'll increase the value of the max_connections system...

Have you ever tried to improve the performance of a query by adding a new index to a table with a large number of rows, waited for ages while the index is built, only to discover that it didn't really help as much as you'd like? Or perhaps you have had an index that you have a hunch isn't doing much to help your query performance and decided to drop it, only to have a bunch of users complain that their queries are stalling? If so, then you will appreciate a nice new feature in...

Have you ever tried to improve the performance of a query by adding a new index to a table with a large number of rows, waited for ages while the index is built, only to discover that it didn't really help as much as you'd like? Or perhaps you have had an index that you have a hunch isn't doing much to help your query performance and decided to drop it, only to have a bunch of users complain that their queries are stalling? If so, then you will appreciate a nice new feature in...

For many programming languages, it's pretty easy to figure out which Connector to use. Java has Connector/J, if you're using C# or ASP you'll opt for Connector/.NET: the clue is in the name. For PHP however, things aren't quite so straightforward. If you want to write a PHP application that communicates with a MySQL database, you have a choice of PHP extensions that you can use: mysql, mysqli, and PDO_MySQL. We can simplify that list right away by discounting the mysql extension...

For many programming languages, it's pretty easy to figure out which Connector to use. Java has Connector/J, if you're using C# or ASP you'll opt for Connector/.NET: the clue is in the name. For PHP however, things aren't quite so straightforward. If you want to write a PHP application that communicates with a MySQL database, you have a choice of PHP extensions that you can use: mysql, mysqli, and PDO_MySQL. We can simplify that list right away by discounting the mysql extension...

We've been busy in the MySQL Curriculum team and are pleased to announce the recent update of the MySQL Performance Tuning course. This course has been substantially revised to take advantage of the performance enhancements available in MySQL 5.7, including new Performance Schema instrumentation and improvements in InnoDB and the Query Optimizer. Even more so than in previous versions of the course, we try to filter out what's "nice to know" and focus on the really...

We've been busy in the MySQL Curriculum team and are pleased to announce the recent update of the MySQL Performance Tuning course. This course has been substantially revised to take advantage of the performance enhancements available in MySQL 5.7, including new Performance Schema instrumentation and improvements in InnoDB and the Query Optimizer. Even more so than in previous versions of the course, we try to filter out what's "nice to know" and focus on the really...

Like any mature technology that is constantly evolving, MySQL has amassed a jargon of its own. Some of this terminology occasionally causes confusion, especially when two terms are similar, but actually refer to two completely different things. This is particularly the case for the two storage engines InnoDB and NDB (which sound very alike when spoken aloud), and the two "Cluster" technologies: InnoDB Cluster and MySQL Cluster. Let's see if we can clear this confusion up. InnoDB ...