On our job schedule system. Using osc-tool cause deadlock problem.
We investigated the root cause in detail and published this PDF doc.

OSC_DDL_PROBLEM

A query plan uses loose index scan if “Using index for group-by” appears in the “Extra”  column of the EXPLAIN output. In some plans though, “Using index for group-by (scanning)” appears. What does “(scanning)” mean and how is it different from the regular loose index scan?…

Actually, Mysqlbinlog tools can’t miner mysql binlog exactly correct.

In this post ,a special environment we got may hexadecimal characters what we don’t need.

Read this PDF: Special-code-rollback.pdf

In MySQL 8.0, we are making large changes to the way the MySQL server stores meta data with the introduction of our native data dictionary. As part of these improvements, we have also made changes to the way the server bootstraps.…

Introduction

This is the final installment of a five part blog series to explore InnoDB internals by looking at the related tunable system variables. In this section we’re going to cover variables that relate to enforcing data consistency, and how index statistics are handled and stored.

Just like previous sections, I would like to emphasize something that was written in part one of this blog post series.

“I should note that while tuning recommendations are provided, this objective of this blog post series was NOT meant to be a tuning primer, but instead to explore the mechanics that each variable interacts with. As such I would like to advise against reading this guide and trying to fine tune all of the available InnoDB variables. System variable tuning is an exercise in diminishing returns, the most benefit you’ll get out of tuning your MySQL server will occur within the first 15 minutes of configuration. In …

Introduction

This is part four of a five part blog series to explore InnoDB internals by looking at the related tunable system variables. In this section we’re going to explore the mechanics that impact CPU resourcing and how InnoDB handles concurrent threads. You’ll notice that a lot of the variables covered in section relate to features that are now disabled but were a lot more prevalent in previous versions of MySQL, particularly those that were released at a time where system context switching had a greater cost than it does today. These variables are still worth discussing as you may run into older systems that utilize these mechanics, and there are even modern systems I’ve worked with that have implemented these features to tune performance to its highest potential.

Just like previous sections, I would like to emphasize something that was written in part one of this blog post series.

“I should note that …

Introduction

A couple of months ago I decided to give myself a refresher on the mechanics of InnoDB. Having a high level understanding of what’s going on under the hood can help provide the context needed in order to resolve issues you may encounter as well as assist you in ensuring that your MySQL instance is running efficiently. Everyone can stand to go back to basics every now and then, as it can help you pick up concepts that you may have missed the last time you researched the topic.

This time around I decided to give myself a refresher by re-reading the MySQL 5.6 reference manual, chapter 14, which covers the InnoDB engine. Despite having a wealth of documented knowledge and insights, I found that a lot of the points in the documentations were unclear, leading me to do more research and experimentation in order to get a bit of clarity on some of the specifics that I felt were missing. In order to help make the information …

MariaDB TokuDB benchmark on FusionIO ,Compare TokuDB and InnoDB engines.

read: TokuDB_benchmark

Description:

I create a empty table and then alter this table's "AUTO_INCREMENT" starts from 10000000.After a long time ,MySQL lost "AUTO_INCREMENT" definition when I show this table again. MariaDB has the same problem but Percona Server is fine.

$mysql06

Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 141028725
Server version: 5.6.17-log MySQL Community Server (GPL)

Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use test;
Reading table information for …

Benchmark for NVMFS (supports atomic writes ,so we can close double-write option on specific MySQL version )

tips: some Flash-based cards could support large block map , the main idea is to avoid fractured page writes.

http://www.vmcd.org/docs/nvmfs_benchmark.pdf