Sql/Psm

MariaDB/MySQL Stored Language is called SQL/PSM.
There are 4 different types of Stored Language: Stored Procedures, Stored Functions, Triggers and Events.

Stored Procedures

Stored Procedure with a Cursor:

DELIMITER //
CREATE PROCEDURE cleanup(IN pData VARCHAR(48))
BEGIN
  DECLARE vId INTEGER;
  DECLARE vNotFound INTEGER;

  DECLARE cCleanUp CURSOR FOR
    SELECT id FROM test WHERE data = pData;

  DECLARE CONTINUE HANDLER FOR NOT FOUND
    SET vNotFound = 1;
  
  OPEN cCleanUp;
  lGetRecord: LOOP …

The General Query Log in MariaDB is a Log (file or table) that logs every statement sent from the Application to the MariaDB Database Server from the Connect Command to the Quit Command. A simple example you can find here:

bin/mysqld, Version: 10.4.6-MariaDB-log (MariaDB Server). started with:
Tcp port: 3306  Unix socket: /var/run/mysqld/mysql.sock
Time                Id Command  Argument
190709 21:27:30   3872 Connect  root@localhost as anonymous on test
                  3872 Query    INSERT INTO test …

MySQL hosting providers can easily loose the overview over their customers and which user or schema is still in use and which not.

The MySQL database becomes bigger and bigger, uses more and more RAM and disk space and the backup takes longer and longer.

In this situation it would be nice to know which MySQL database user has logged in within the last 6 months for example. MySQL database users who did not login within a defined period can be backuped and removed from the production MySQL database.

The …

Abstract: In this article we discuss how big is the performance impact of MySQL TRIGGERs compared to application side logging (with INSERT) into a MySQL table.

What was in my mind from the past

A while ago when MySQL released its Stored Language features in v5.0 I have seen a book
[1
] about this topic. In this book was a performance comparison between different implementations of computational tasks, one was done in MySQL Stored Language. The result was, that MySQL Stored Language feature sucks also …

A while ago I did some research about MySQL audit functionality and logon a and logoff triggers. MySQL and MariaDB provide a logon trigger in the form of the init_connect variable but no logoff trigger where most of the work for auditing would be done. When we would have a logoff trigger we could track the login and possibility some activity of a user and implement auditing functionality.

Yesterday when I was looking into the code for an answer to the question of one of my customers this research came into …

Table of Contents

• What is a Materialized View?
• Implement your own Materialized Views
• Refreshing materialized views
• Hands on
• Create your own Materialized View:
• Refresh Materialized View on demand
• Refresh Materialized View immediate
• Materialized Views with snapshotting functionality
• Some performance benchmarks for our Materialized Views:
• Outlook
• Conclusion
• Literature

What is a Materialized View?

A Materialized View (MV) is the pre-calculated (materialized) result of a query. Unlike a simple VIEW the result …