If you have worked with an RDBMS for some time, you will likely have come across the statement SELECT 1.

However, rarely is it correctly explained to engineers what the origin of SELECT 1 is, and why it’s useless and wasteful? A google search is not going to give you the response you would hope, these ranked responses are just as useless as the statement itself.

Bloat

Seeing a SELECT 1 confirms two things. First you are using a generic ORM framework, quote, and second, you have never optimized your SQL traffic patterns.

“Frameworks generally suck.
They CLAIM to improve the speed of development and abstract the need to know SQL.
The REALITY is the undocumented cost to sub-optimal performance, especially with data persistence.”

Connection Pooling

SELECT 1 comes from …

A student wanted a better example of writing a MySQL Persistent Stored Module (PSM) that maintains transactional scope across a couple tables. Here’s the one I wrote about ten years ago to build the MySQL Video Store model. It looks I neglected to put it out there before, so here it is for reference.

-- Conditionally drop procedure if it exists.
DROP PROCEDURE IF EXISTS contact_insert;

-- Reset the delimiter so that a semicolon can be used as a statement and block terminator.
DELIMITER $$

SELECT 'CREATE PROCEDURE contact_insert' AS "Statement";
CREATE PROCEDURE contact_insert
( pv_member_type         CHAR(12)
, pv_account_number      CHAR(19)
, pv_credit_card_number  CHAR(19)
, pv_credit_card_type    CHAR(12)
, pv_first_name          CHAR(20)
, pv_middle_name         CHAR(20)
, pv_last_name           CHAR(20)
, pv_contact_type        CHAR(12)
, pv_address_type        CHAR(12)
, pv_city                CHAR(30)
, pv_state_province      CHAR(30)
, …

MySQL Shell For VS Code integrates the MySQL Shell directly into VS Code development workflows and was released last week. This extension to the popular VS Code platform enables interactive editing and execution of SQL for MySQL Databases and optionally the MySQL Database Service for several simultaneous sessions.  It is a preview release and not ready for production but it does have several features that may make the MySQL GUI of choice.

Installation

The installation itself is easy but you will need to download the code from here and not the usual places for MySQL products.  You will, of course, have to have VS Code installed first, and be warned that some of the more tantalizing links for things like documentation are not connected.

MySQL Shell for VS Code installation screen and yes, you will need VS Code installed first.

Usage

The interface is familiar to that of MySQL Workbench but …

I recently needed to add multiple columns to an existing table to store summary data calculations and wondered if I could do it in one MySQL ALTER TABLE statement. Turns out you can. And, it’s super simple. Convenient too. Continue reading and learn what I learned…

Image by Gerd Altmann from Pixabay 

The Newsletter for PHP and MySQL Developers

Receive a copy of my ebook, “10 MySQL Tips For Everyone”, absolutely free when you …

The utf8mb4 character set is the new default as of MySQL 8.0, and this change neither affects existing data nor forces any upgrades.

Migration to utf8mb4 has many advantages including:

• It can store more symbols, including emojis
• It has new collations for Asian languages
• It is faster than utf8mb3

Still, you may wonder how migration affects your existing data. This blog covers multiple aspects of it.

Storage Requirements

As the name suggests, the maximum number of bytes that one character can take with character set utf8mb4 is four bytes. This is larger than the requirements for utf8mb3 which takes three bytes and many other MySQL character sets.

Fortunately, utf8mb3 is a subset of …

I’ve once again published a massive issue of the OpenLampTech newsletter, the newsletter for PHP/MySQL developers. If you’re looking to learn more about PHP and MySQL, you’ve come to the right place…

Image by Clker-Free-Vector-Images from Pixabay

The Newsletter for PHP and MySQL Developers

Receive a copy of my ebook, “10 MySQL Tips For Everyone”, absolutely free when you subscribe to the …

On 22nd March 2022 08:43 UTC, we became aware of the issue affecting Okta, a third-party identity provider that Percona uses for https://id.percona.com. Initially, there was no statement from Okta, so our Security Operations team reviewed the information available from LAPSUS$ and other public sources.

Based on the public information available about the issue, we evaluated the potential exposure to Percona and determined that the impact was minimal. Percona uses Okta integrations so https://id.percona.com can be used to authenticate against Percona’s deployments of:

• forums.percona.com (Discourse)
• percona.service-now.com (ServiceNow) 
• portal.percona.com (Dashboard portal interface where users & clients can add their PMM integration). 

Integrations of …

For a very long part of its history, MySQL replication has been limited in terms of performance. Because there was no way of knowing if transactions or updates were independent, the updates had to be executed on a replica following the exact same sequence of operations as on the primary server. The only way to guarantee the same sequence of operations on the replica was to use a single thread. In this post, we’ll do a dive into the MySQL multi-threaded replication (MTR) implementation and explore the available tuning options.

MTR is the culmination of the evolution in the development of parallel replication which followed the path:

1. Single-threaded replication
2. Per-database replication
3. Logical clock replication

We’ll leave aside, for now, the recent dependency tracking feature.

Context

Before we discuss the multi-threaded implementation, let’s review in …

In MySQL, the @@sql_mode parameter should generally use ONLY_FULL_GROUP_BY. If it doesn’t include it and you don’t have the ability to change the database parameters, you can use a MySQL PSM (Persistent Stored Module), like:

Create the set_full_group_by procedure:

-- Drop procedure conditionally on whether it exists already.
DROP PROCEDURE IF EXISTS set_full_group_by;

-- Reset delimter to allow semicolons to terminate statements.
DELIMITER $$

-- Create a procedure to verify and set connection parameter.
CREATE PROCEDURE set_full_group_by()
  LANGUAGE SQL
  NOT DETERMINISTIC
  SQL SECURITY DEFINER
  COMMENT 'Set connection parameter when not set.'
BEGIN

  /* Check whether full group by is set in the connection and
     if unset, set it in the scope of the connection. */
  IF NOT EXISTS
    (SELECT NULL
     WHERE  REGEXP_LIKE(@@SQL_MODE,'ONLY_FULL_GROUP_BY'))
  THEN
    SET SQL_MODE=(SELECT CONCAT(@@sql_mode,',ONLY_FULL_GROUP_BY'));
  END IF; …

As part of my ongoing series around MySQL 8 user administration, I’d like to cover one of the new features introduced in MySQL 8.0.27 – multi-factor authentication. In order to establish identity, multi-factor authentication (MFA) is the use of multiple authentication values (factors) during the MySQL authentication process.

Introduction

MFA provides greater security compared to a single-factor authentication method, which has historically been based on simple methods such as password authentication. With MFA, additional authentication methods are enabled, such as requiring multiple passwords, or with devices such as smart cards, security keys, or biometric readers.

As of MySQL 8.0.27, it is now possible to require up to three authentication values to establish identity. In addition to the more common 2FA (two-factor authentication), MySQL can now also support 3FA (three-factor authentication) to complement the …