EmergencyEMERGENCY? Get 24/7 Help Now!

Updating InnoDB Table Statistics Manually

 | September 11, 2017 |  Posted In: Database Monitoring, InnoDB, Insight for DBAs, Insight for Developers, MySQL

InnoDB Tables

In this post, we will discuss how to fix cardinality for InnoDB tables manually. As a support engineer, I often see situations when the cardinality of a table is not correct. When InnoDB calculates the cardinality of an index, it does not scan the full table by default. Instead it looks at random pages, as determined […]

Read More

Migrating Data from an Encrypted Amazon MySQL RDS Instance to an Encrypted Amazon Aurora Instance

 | August 23, 2017 |  Posted In: Aurora RDS, Cloud and MySQL, MySQL

Migrating Data

In this blog post, we’ll discuss migrating data from encrypted Amazon MySQL RDS to encrypted Amazon Aurora. One of my customers wanted to migrate from an encrypted MySQL RDS instance to an encrypted Aurora instance. They have a pretty large database, therefore using mysqldump or a similar tool was not suitable for them. They also wanted to setup […]

Read More


 | May 11, 2017 |  Posted In: MyRocks, MySQL, Technical Webinars


In this blog post, we’ll look at MyRocks and the LOCK IN SHARE MODE. Those who attended the March 30th webinar “MyRocks Troubleshooting” might remember our discussion with Yoshinori on  LOCK IN SHARE MODE. I did more tests, and I can confirm that his words are true: LOCK IN SHARE MODE works in MyRocks. This quick example demonstrates this. The initial setup:

In session 1:


Read More

Open Source Databases on Big Machines: Disk Speed and innodb_io_capacity

 | March 1, 2017 |  Posted In: MySQL, open source databases, OpenSource Databases on big machines

In this blog post, I’ll look for the bottleneck that prevented the performance in my previous post from achieving better results. The powerful machine I used in the tests in my previous post has a comparatively slow disk, and therefore I expected my tests would hit a point when I couldn’t increase performance further due to the disk speed. […]

Read More

MySQL Bug 72804 Workaround: “BINLOG statement can no longer be used to apply query events”

 | February 16, 2017 |  Posted In: MySQL

MySQL Bug 72804

In this blog post, we’ll look at a workaround for MySQL bug 72804. Recently I worked on a ticket where a customer performed a point-in-time recovery PITR using a large set of binary logs. Normally we handle this by applying the last backup, then re-applying all binary logs created since the last backup. In the middle of the […]

Read More

Performance Schema Benchmarks: OLTP RW

 | January 26, 2017 |  Posted In: MySQL, open source databases, OpenSource Databases on big machines

Performance Schema Benchmarks

In this blog post, we’ll look at Performance Schema benchmarks for OLTP Read/Write workloads. I am in love with Performance Schema and talk a lot about it. Performance Schema is a revolutionary MySQL troubleshooting instrument, but earlier versions had performance issues. Many of these issues are fixed now, and the default options work quickly and […]

Read More

Open Source Databases on Big Machines: Does READ COMMITTED Scale on 144 Cores?

 | January 19, 2017 |  Posted In: open source databases, OpenSource Databases on big machines


In the second post in my series on open source databases on big machines, we’ll look at whether READ COMMITTED scales with multiple cores. The default transaction level for InnoDB is REPEATABLE READ. A more permissive level is  READ COMMITTED, and is known to work well. While the  REPEATABLE READ level maintains the transaction history up to the start of the transaction, […]

Read More