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MySQL 8.0: ひらがなカタカナを判別する日本語用Collation

以前の記事では、MySQL 8.0.1で導入された新しい 日本語のutf8bm4のCollation(文字照合順)について ご紹介しました。このcollation (utf8mb4_ja_0900_as_cs) は、CLDR 30で定義されたアクセント記号(清音濁音半濁音)ならびに大文字小文字(拗音促音など)を判別する実装となっています。

今日ご紹介するのはひらがなカタカナを判別できる新しい「かなセンシティブ」なCollation utf8mb4_ja_0900_as_cs_ksです。 …

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MySQL8.0: 日本語のutf8bm4のCollation(文字照合順)

MySQL 8.0.1では、utf8mb4の大文字小文字およびアクセント記号付きの文字を判別するas_cs collationに加えて、日本語用のCollation(文字照合順)を追加しました。


日本語に関する文字照合およびソートのルールは複雑です。日本語ではひらがな、カタカナ、漢字、アルファベット(ラテン文字)を混在させて利用しています。さらに、全角と半角が存在する文字もあります。では、‘あ’, ‘ア’, ‘a’, ‘ア’はどのようにソートされるのでしょうか?

Unicode照合アルゴリズム(UCA / Unicode Collation …

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Schema Sharding with MariaDB MaxScale 2.1 - Part 1

Schema Sharding with MariaDB MaxScale 2.1 - Part 1 Wagner Bianchi Fri, 06/23/2017 - 08:45

Most of the time when you start a database design you don’t imagine how your applications need to scale. Sometimes, you need to shard your databases among some different hosts and then, on each shard you want to split reads and writes between master and slaves. This blog is about MariaDB MaxScale being able to handle different databases across shards, and splitting up reads and writes into each of the shards to achieve the maximum level of horizontal scalability with MariaDB Server.

After reading this blog you will be able to:

  • Know how MariaDB MaxScale handles shards with …

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How to backup MySQL 5.7

If you ever tried to backup MySQL 5.7 with Percona Xtrabackup that comes in percona-xtrabackup package most likely you got error message like this:

# innobackupex ./
170623 05:58:43 innobackupex: Starting the backup operation

IMPORTANT: Please check that the backup run completes successfully.
At the end of a successful backup run innobackupex
prints "completed OK!".

170623 05:58:44 version_check Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_group=xtrabackup' as 'dba' (using password: YES).
170623 05:58:44 version_check Connected to MySQL server
170623 05:58:44 version_check Executing a version check against the server...
170623 05:58:44 version_check Done.
170623 05:58:44 Connecting to MySQL server host: localhost, user: dba, password: set, port: not set, socket: not set
Error: Unsupported server version: '5.7.18-15'. Please report a bug at

This happens because …

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ClickHouse in a General Analytical Workload (Based on a Star Schema Benchmark)

In this blog post, we’ll look at how ClickHouse performs in a general analytical workload using the star schema benchmark test.

We have mentioned ClickHouse in some recent posts (ClickHouse: New Open Source Columnar Database, Column Store Database Benchmarks: MariaDB ColumnStore vs. Clickhouse vs. Apache Spark), where it showed excellent results. ClickHouse by itself seems to be event-oriented RDBMS, as its name suggests (clicks). Its primary purpose, using Yandex Metrica (the system similar to Google Analytics), also points to an event-based nature. We also can see there is …

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Debian 9 and MySQL: Watch Out!

Debian logo by Software in the Public Interest, Inc. (CC-BY-SA) MySQL and Debian 9 “Stretch” Debian 9 (“Stretch”) was released on June 17, and we congratulate the Debian community on another iteration of a central Linux distro. Now, the Debian release team some time ago decided not to ship MySQL as part of the distro, instead replacing it […]

How to Install LAMP on Ubuntu 16.04

LAMP (Linux, Apache, MySQL, PHP) is a combination of open source software, typically installed on a server used for hosting dynamic websites and web applications. It includes the Linux operating system, the Apache web server, MySQL for data storage and management and PHP for handling the dynamic content. In this tutorial, we will go through a complete LAMP installation on a Ubuntu 16.04 based VPS. Requirements SSH access with root privileges to your server, as well as an Ubuntu 16.04 VPS is required for you to be able to complete all the steps in this tutorial. 1. Update your system […]

How to resize a VirtualBox VDI file on Mac OS

Recently, I had to do this as 10GB was not sufficient for Centos6.7 VM. I would just like to mention simple steps for how to do it.

  1. Shutdown VM and quit from VirtualBox.
  2. Open the terminal and go to the below path (default location). From here you can run the command to resize the VDI file.
    Nils-Mac:MacOS nilnandan$ pwd
    Nils-Mac:MacOS nilnandan$ 
  3. Start another terminal with command + T and find the directory where actually the VDI file stored. Default location would be ,
    Nils-Mac:centos67-mysql nilnandan$ pwd
    /Users/nilnandan/VirtualBox VMs/centos67-mysql
    Nils-Mac:centos67-mysql nilnandan$ ls -alh
    total 21925920
    drwx------   7 nilnandan  staff   238B Aug 11 18:15 .
    drwx------  12 nilnandan  staff   408B Aug 11 17:50 …
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Linux perf and the CPU regression in MySQL 5.7

I used Linux perf to get more details on system performance while running the point-query test with modern sysbench. This is for an in-memory workload and part of my series on low-concurrency CPU regressions for bug 86215.


  • I have more explaining to do
  • The increase in instructions/query explains the decrease in queries/second from MySQL 5.6 to 5.7 to 8.0.


I tested MySQL using upstream 5.6.35, 5.7.17 and 8.0.1. For 8.0.1 I used the latin1 charset and latin1_swedish_ci collation. My servers are  …

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Secure Binlog Server: Encrypted binary Logs and SSL Communication

Secure Binlog Server: Encrypted binary Logs and SSL Communication massimiliano_pinto_g Wed, 06/21/2017 - 19:23

The 2.1.3 GA release of MariaDB MaxScale, introduces the following key features for the secure setup of MaxScale Binlog Server:

  • The binlog cache files in the MaxScale host can now be encrypted.

  • MaxScale binlog server also uses SSL in communication with the master and the slave servers.

The MaxScale binlog server can optionally encrypt the events received from the master server: the setup requires a MariaDB (from 10.1.7) master server with encryption active and the mariadb10-compatibility=On option set in maxscale.cnf. This way both master and MaxScale will have encrypted events stored in the binlog files. How does the Binary log …

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