Shinguz's blog

The number of table definitions (SHOW CREATE TABLE<br>G) that can be stored in the table definition cache (table_definition_cache). If you have a large number of tables (
> 400) in your database instance, you should consider a larger table definition cache to increase your database throughput and decrease your query latency.
The command SELECT COUNT(*) FROM information_schema.tables; shows you how many tables and thus table definitions you have. The global status Open_table_definitions is the current amount of open table definitions.

The Table Open Cache (table_open_cache or old name table_cache) is a cache to store file handles for all threads. The actual value of cache entries can be seen with the global status of open tables (Open_tables).
Increasing table_open_cache increases the number of file descriptors (open_files_limit) that MySQL requires.
You can check whether you need to increase the Table Open Cache by checking Open_tables and Opened_tables. If the value of Opened_tables is large and you do not use FLUSH TABLES often (which just forces all tables to be closed and reopened), then you should increase the value of the table_open_cache variable.

If and how to use Galera Cluster for MySQL has been described already by many others…

Database migration tools

A generic database migration tool to MySQL and MariaDB is the MySQL Workbench.

The InnoDB Flush Method has changed. This can have an impact on InnoDB write Performance.

FromDual has the pleasure to announce the release of the new version 1.2.2 of the popular Backup and Recovery Manager for MySQL and MariaDB (fromdual_bman).

Correct is a question of definition... I suggest starting with the following command for a full backup:

The following example should work for you:

CREATE TABLE spec(txt VARCHAR(255));

A MySQL customer of FromDual has different manufacturing plants spread across the globe. They are operated by local companies. FromDuals customer wants to maintain the manufacturing receipts centralized in a MySQL database in the Head Quarter in Europe. Each manufacturing plant should only see their specific data.

We finally got the results. The table does NOT have a Primary Key and/or an index on lSessionId:

We typically suggest our customers to use our MySQL/Galera Cluster my.cnf configuration template to avoid MySQL configuration and performance problems.

From time to time we see at Galera Cluster customer engagements the following, for me scary, warning in the MySQL error log:

Before I forget it and have to search again here a short note about how to rename a MySQL Partition:

This error is NOT serious. It happens, when one MPM run overpasses an older one or when you start a second run manually.

MySQL Enterprise Backup (MEB) has the capability to make real incremental (differential and cumulative?) backups. The actual releases are quite cool and you should really look at it…

Hi burps

In Zabbix we have “hosts”. In MPM a host is either a server (DBSERVER01) or a MySQL Instance (mysqld).

MySQL Enterprise Monitor (MEM) has by default no Event Handlers created and activated. These Event Handlers you have to define yourself according to your needs.

FromDual has the pleasure to announce the release of the new version 1.0.0 of its widely used Nagios and Icinga plugins for MySQL, Galera Cluster, MariaDB and Percona Server.

MySQL provides some great enterprise features beside the MySQL Server. The ones we are asked the most at customers are:

Sometimes we face the situation where we have a full MySQL database backup done with mysqldump and then we have to restore and recover just one single table out of our huge mysqldump file.
Further our mysqldump backup was taken hours ago so we want to recover all the changes on that table since our backup was taken up to the end.