This video tutorial describes how to install Galera Manager in 15 minutes while also deploying a Galera Cluster in Amazon Web Services (AWS), all in an automated fashion!

WATCH THE VIDEO

As more people test, utilise and deploy Galera Manager, there is always room for support requests, and we see that at the Galera Manager Support Repository on Github. We encourage you to file requests, as they help with our roadmap as well!

We have had a feature request to run within a Docker container, and while we work on documentation and an official solution, we do have a temporary solution. Try it with Docker!

We have had a feature request to be able to support …

MySQL 8.0.27 introduced a new variable to control the maximum of parallel threads InnoDB can use for creating (sorting and building) secondary indexes: innodb_ddl_threads.

This new variable is coupled with another new variable: innodb_ddl_buffer_size.

If you have fast storage and multiple CPU cores, tuning these variables can speed up secondary index creation.

For this example, I used the airportdb database, and I added a secondary index to the largest table, booking.

Let’s start with the default settings:

 SQL  alter table booking …

In this article learn how to improve the creation of InnoDB secondary indexes in MySQL 8.0.

Working on a real case scenario in a five node Percona XtraDB Cluster (PXC), we were forced to use wsrep_sync_wait = 1, because the app does reads-after-write and we send reads to all the nodes. We had the idea to leave some nodes in DESYNC mode to reduce the flow control messages during peak load and expected to have a steadier write throughput keeping the read consistency.

We decided to test Perconas’s new PXC Scheduler Handler which is an application that manages integration between ProxySQL and Galera/PXC (the scope is to maintain the ProxySQL mysql_server table, if a negative scenario occurs, like: failures, service degradation, and maintenance). However, we realized that when a node is in DESYNC mode, it is kicked out of the read hostgroup. That is …

In reply to a question about how to conditionally drop an index on a table in MySQL. It appears the syntax doesn’t exist. However, maybe it does and I missed it. If I did miss it, I’m sure somebody will let me know. However, I simply have a dropIndexIfExists stored procedure for this type of database maintenance.

Below is my dropIndexIfExists stored procedure:

-- Conditionally drop the procedure.
DROP PROCEDURE IF EXISTS dropIndexIfExists;

-- Change the default semicolon delimiter to write a PSM
-- (Persistent Stored Module) or stored procedure.
DELIMITER $$

-- Create the procedure.
CREATE PROCEDURE dropIndexIfExists
( pv_table_name  VARCHAR(64)
, pv_index_name  VARCHAR(64))
BEGIN

  /* Declare a local variable for the SQL statement. */
  DECLARE stmt VARCHAR(1024);

  /* Set a session variable with two parameter markers. */
  SET @SQL := CONCAT('ALTER TABLE ',pv_table_name,'DROP INDEX ',pv_index_name);

  /* Check if the constraint exists. …

I was working through some tutorials for my students and noticed that there was a change in how a WHERE clause must be written against the information_schema.table_constraints table. It might have been made in an earlier release, I actually hadn’t checked it since 2014 when I wrote this early post on capturing MySQL Foreign Keys.

You could use the following WHERE case insensitive clause:

WHERE    tc.constraint_type = 'foreign key'

Now, you must use a case sensitive WHERE clause:

WHERE    tc.constraint_type = 'FOREIGN KEY'

I’d love to know why but I can’t seem to find a note on the change. As always, I hope this helps those looking for an answer.

A year ago, I blogged about An Unprivileged User can Crash your MySQL Server.  At the time, I presented how to protect yourself against this problem without explaining how to generate a crash.  In this post, I am revisiting this vulnerability, not giving the exploit yet, but presenting the fix.  Also, because the default configuration of Group Replication in 5.7 is still vulnerable

New research combined with anecdotal information suggest the traditional kick-off to the holiday shopping season may have run its course.

MySQL is an open-source relational database management system (RDBMS), it’s widely used and part of the popular LAMP/LEMP stacks. The ...

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