The tables in PERFORMANCE_SCHEMA (P_S) are not actually tables. You should not think of them as tables, even if your SQL works on them. You should not JOIN them, and you should not GROUP or ORDER BY them.

Unlocked memory buffers without indexes

The stuff in P_S has been created with “keep the impact on production small” in mind. That is, from a users point of view, you can think of them as unlocked memory buffers – the values in there change as you look at them, and there are precisely zero stability guarantees.

There are also no indexes.

Unstable comparisons

When sorting a table for a GROUP BY or ORDER BY, it may be necessary to compare the value of one row to other rows multiple times in order to determine where the row goes. The value compared to other rows can change while this happens, and will change more often the more load the server has. The end …

The tables in PERFORMANCE_SCHEMA (P_S) are not actually tables. You should not think of them as tables, even if your SQL works on them. You should not JOIN them, and you should not GROUP or ORDER BY them.

Unlocked memory buffers without indexes

The stuff in P_S has been created with “keep the impact on production small” in mind. That is, from a users point of view, you can think of them as unlocked memory buffers - the values in there change as you look at them, and there are precisely zero stability guarantees. There are also no indexes.

Unstable comparisons

When sorting a table for a GROUP BY or ORDER BY, it may be necessary to compare the value of one row to other rows multiple times in order to determine where the row goes. The value compared to other rows can change while this happens, and will change more often the more load the server has. The end result is …

At work, I am in an ongoing discussion with a number of people on the Observability of Outliers. It started with the age-old question “How do I find slow queries in my application?” aka “What would I want from tooling to get that data and where should that tooling sit?”

As a developer, I just want to automatically identify and isolate slow queries!

Where I work, we do have SolarWinds Database Performance Monitor aka Vividcortex to find slow queries, so that helps. But that collects data at the database, which means you get to see slow queries, but maybe not application context.

There is also work done by a few developers which instead collects query strings, query execution times and query counts at the application. This has access to the call stack, so it can tell you which code generated the query that was slow.

It …

At work, I am in an ongoing discussion with a number of people on the Observability of Outliers. It started with the age-old question “How do I find slow queries in my application?” aka “What would I want from tooling to get that data and where should that tooling sit?”

As a developer, I just want to automatically identify and isolate slow queries!

Where I work, we do have SolarWinds Database Performance Monitor aka Vividcortex to find slow queries, so that helps. But that collects data at the database, which means you get to see slow queries, but maybe not application context. There is also work done by a few developers which instead collects query strings, query execution times and query counts at the application. This has access to the call stack, so it can tell you which code generated the query that was slow. It also channels this …

I am always surprised to learn something new whenever I talk to a member of the open-source community. No matter how much I think I have heard of every use case there is for Liquibase (and database change management in general), I always hear something that makes this space still feel new. There’s always something left to discover.

Today, that new something is the problem of how to perform large batches of changes with SQL ALTER TABLE statements. No problem you say? Okay, but this ALTER needs to happen in production. Still not worried? Well, let’s say you have millions of rows, and because you’re so successful, you have many transactions happening per minute (maybe even per second). Yeah…now we are talking. You can’t alter the table because you can’t afford to lock that table for the …

I am always surprised to learn something new whenever I talk to a member of the open-source community. No matter how much I think I have heard of every use case there is for Liquibase (and database change management in general), I always hear something that makes this space still feel new. There’s always something left to discover.

Today, that new something is the problem of how to perform large batches of changes with SQL ALTER TABLE statements. No problem you say? Okay, but this ALTER needs to happen in production. Still not worried? Well, let’s say you have millions of rows, and because you’re so successful, you have many transactions happening per minute (maybe even per second). Yeah…now we are talking. You can’t alter the table because you can’t afford to lock that table for the …

Percona Live Online Agenda Slot: Wed 21 Oct • New York 7:30 a.m. • London 12:30 p.m. • New Delhi 5:00 p.m. • Singapore 7:30 p.m.

Abstract

ProxySQL is a high performance, high available, protocol aware proxy for MySQL. 2.0 has been GA for some time now, and there have been a lot of changes that come in point releases as well, such that you can benefit from them.

Listen to René, the founder of ProxySQL, take you through some of the new features in 2.0, and how you can effectively utilize them. Some topics that are covered include:

– LDAP authentication
– SSL for client connections
– AWS Aurora usage
– Native clustering support for Percona XtraDB Cluster (PXC) / Galera Cluster / group replication
– Kubernetes deployments

This is the talk to take you from intermediate ProxySQL user to …

Percona Live Online Agenda Slot: Wed 21 Oct • New York 7:30 a.m. • London 12:30 p.m. • New Delhi 5:00 p.m. • Singapore 7:30 p.m.

Abstract

ProxySQL is a high performance, high available, protocol aware proxy for MySQL. 2.0 has been GA for some time now, and there have been a lot of changes that come in point releases as well, such that you can benefit from them. Listen to René, the founder of ProxySQL, take you through some of the new features in 2.0, and how you can effectively utilize them. Some topics that are covered include: - LDAP authentication - SSL for client connections - AWS Aurora usage - Native clustering support for Percona XtraDB Cluster (PXC) / Galera Cluster / group replication - Kubernetes deployments This is the talk to take you from intermediate ProxySQL user to expert in the 2.0 feature set. There will also be talk about the …

Creating the database for an application is simple and easy. However, database script management gets complicated in a hurry when you need to support multiple versions, work with multiple teams, and apply the same changes to multiple types of databases. 

One open-source tool that helps teams track, version, and deploy database schema changes is Liquibase. It executes database scripts sequentially, allows for the automatic creation and execution of rollback scripts for failed updates, and provides an easy way to use the same scripts and apply them to different types of databases. To illustrate how Liquibase works, here’s an example using PostgreSQL.   

System set up:

• Download the latest version of Liquibase. 
• …

Incorporating a database in an organization is a complicated task that involves a lot of people besides the DBAs. This is something that Peter Zaitsev, co-founder and CEO of Percona, understands very well.

In the build-up to his hands-on presentation with the open source Percona Monitoring and Management (PMM) platform, Peter spoke about how inducting a database in an organization is a constant tussle between the developers, the management and the DBAs. While the developers want a solution that just works, the managers don’t want the database to break the bank: “The DBAs just want to make sure they don’t spend too much time keeping them both happy,” he shared.

This is why, Peter argues, DBAs want to make sure the databases in their realm are optimized for performance. Like security, performance optimization is an …