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Determine amount of memory being used for connection

Lastest Forum Posts - January 23, 2018 - 10:54am
Is it possible to determine the amount of memory mysql is currently holding for all connections combined?

pt-online-schema-change - alter to

Lastest Forum Posts - January 23, 2018 - 5:11am
I Tested the pt-online-schema-change on a sample database employees
with this schema :
CREATE TABLE `employees` (
`emp_no` int(11) NOT NULL,
`birth_date` date NOT NULL,
`first_name` varchar(14) NOT NULL,
`last_name` varchar(16) NOT NULL,
`gender` enum('M','F') NOT NULL,
`hire_date` date NOT NULL,
PRIMARY KEY (`emp_no`)
i want to change the table to a partitioned table based on hire_date and for that i need to change the pk , otherwise i'm getting an error
Error Code: 1503. A PRIMARY KEY must include all columns in the table's partitioning function

pt-online-schema-change --alter "PARTITION BY RANGE (to_days(hire_date)) (PARTITION p0 VALUES LESS THAN (599616000),PARTITION p1 VALUES LESS THAN (662688000),PARTITION p2 VALUES LESS THAN (725846400),PARTITION p3 VALUES LESS THAN (MAXVALUE) )" D=employees,t=employees --execute

so i need to do a work around before at two stages ( that on big tables can take along time )

first :drop primary key ,ADD PRIMARY KEY (emp_no ,hire_date)
and then do the partition change

my question is there a way in using one of the options , or using plugins
to create the temp table copy with the new PK , or avoid this error in some other way


MySQL PID not found?

Lastest Forum Posts - January 23, 2018 - 4:52am
I have been trying to create a three-node percona cluster. The problem is, I am getting this MySQL PID not found in a freshly installed server.
root@debian-s-4vcpu-8gb-sgp1-01:~# sudo service mysql status
● mysql.service - Start and stop the mysql (Percona XtraDB Cluster) daemon
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: inactive (dead) since Tue 2018-01-23 12:46:30 UTC; 3min 33s ago
Process: 5451 ExecStop=/etc/init.d/mysql stop (code=exited, status=0/SUCCESS)
Process: 4969 ExecStart=/etc/init.d/mysql start (code=exited, status=0/SUCCESS)
Process: 4893 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
Main PID: 5007 (code=exited, status=0/SUCCESS)

Jan 23 12:46:07 debian-s-4vcpu-8gb-sgp1-01 systemd[1]: Starting Start and stop the mysql (Percona XtraDB Cluster) daemon...
Jan 23 12:46:12 debian-s-4vcpu-8gb-sgp1-01 systemd[1]: Started Start and stop the mysql (Percona XtraDB Cluster) daemon.
Jan 23 12:46:15 debian-s-4vcpu-8gb-sgp1-01 systemd[1]: Stopping Start and stop the mysql (Percona XtraDB Cluster) daemon...
Jan 23 12:46:30 debian-s-4vcpu-8gb-sgp1-01 /etc/init.d/mysql[5553]: MySQL PID not found, pid_file detected/guessed: /var/run/mysqld/
Jan 23 12:46:30 debian-s-4vcpu-8gb-sgp1-01 systemd[1]: Stopped Start and stop the mysql (Percona XtraDB Cluster) daemon.

Webinar Wednesday, January 24, 2018: Differences between MariaDB and MySQL

Latest MySQL Performance Blog posts - January 22, 2018 - 3:42pm

Join Percona’s Chief Evangelist, Colin Charles as he presents Differences Between MariaDB and MySQL on Wednesday, January 24, 2018, at 7:00 am PDT / 10:00 am EDT (UTC-7).

Register Now

Tags: MariaDB, MySQL, Percona Server for MySQL, DBA, SysAdmin, DevOps
Experience Level: Novice

MariaDB and MySQL. Are they syntactically similar? Where do these two query languages differ? Why would I use one over the other?

MariaDB is on the path of gradually diverging from MySQL. One obvious example is the internal data dictionary currently under development for MySQL 8.0. This is a major change to the way metadata is stored and used within the server. MariaDB doesn’t have an equivalent feature. Implementing this feature could mark the end of datafile-level compatibility between MySQL and MariaDB.

There are also non-technical differences between MySQL and MariaDB, including:

  • Licensing: MySQL offers their code as open-source under the GPL, and provides the option of non-GPL commercial distribution in the form of MySQL Enterprise. MariaDB can only use the GPL because they derive their work from the MySQL source code under the terms of that license.
  • Support services: Oracle provides technical support, training, certification and consulting for MySQL, while MariaDB has their own support services. Some people will prefer working with smaller companies, as traditionally it affords them more leverage as a customer.
  • Community contributions: MariaDB touts the fact that they accept more community contributions than Oracle. Part of the reason for this disparity is that developers like to contribute features, bug fixes and other code without a lot of paperwork overhead (and they complain about the Oracle Contributor Agreement). However, MariaDB has its own MariaDB Contributor Agreement — which more or less serves the same purpose.

Colin will take a look at some of the differences between MariaDB and MySQL and help answer some of the common questions our Database Performance Experts get about the two databases.

Register for the webinar now.

Colin Charles, Chief Evangelist

Colin Charles is the Chief Evangelist at Percona. He was previously on the founding team for MariaDB Server in 2009, worked in MySQL since 2005, and been a MySQL user since 2000. Before joining MySQL, Colin worked actively on the Fedora and projects. He’s well-known within many open source communities and speaks on the conference circuit.


Lastest Forum Posts - January 21, 2018 - 11:45pm
May I ask why I did not do semi-synchronous monitoring

Percona for mariadb 10.x?

Lastest Forum Posts - January 21, 2018 - 6:17pm
I am using MariaDB 10.1
Can i use percona server?

I have 8 core server. But Mariadb is using only one core. All 7 cores are remaining idle.
Please guide me to install Percona Server.

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