The latest from the MySQL community

Query tuning is something that a DBA does on a daily basis - analyse queries and updates, how these interact with the data and schema, and optimize for performance. This is an extremely important task as this is where database performance can be significantly improved - sometimes by orders of magnitude. 

In the next few posts, we will cover the basics of query tuning - indexing, what types of queries to avoid, optimizer hints, EXPLAIN and execution plans, schema tips, and so on. We will start, though, by discussing the process of query review - how to gather data and which methods are the most efficient.

This is the ninth installment in the 'Become a MySQL DBA' blog series. Our previous posts in the DBA series include Configuration Tuning, …

Previous episodes:

• MySQL replication monitoring 101

MySQL replication in action - Part 1: GTID & CoMySQL replication in action - Part 2 - Fan-in topology


In the previous article, we saw the basics of establishing replication from multiple origins to the same destination. By extending that concept, we can deploy more complex topologies, such as the point-to-point (P2P) all-masters topology, a robust and fast …

The following passage is excerpted from the VividCortex eBook The Strategic IT Manager’s Guide to Building a Scalable DBA Team, by Baron Schwatrz. This eBook offers Baron’s expert insights and opinions on how top-performing companies manage vast amounts of data, while keeping it secure, available, and performant. The highlighted section examines how a company can look to its DBAs for clues about its greater IT systems, and what these clues might mean about the company in a larger sense. Consider why “DBAs are the canaries in the coal mine” and what you should do with the very valuable information their experiences yield.

To read more from this eBook, you can download a free copy here.

Why DBAs are Canaries in the Coal Mine

If yours is a data-driven organization, your DBAs probably …

Why DBAs are Canaries in the Coal Mine

If yours is a data-driven organization, your DBAs probably face significant challenges to executing effectively. These typically include the following:

• The scale and growth of the data. You know that data is big and growing fast, but you might not realize that DBAs are often expected to handle it without an increase in resources. In other words, the data-to-human ratio is growing rapidly.

• Emerging technologies, which often lack the mature tools DBAs rely on for productivity.

• The diversity and complexity of databases and application architectures. Polyglot persistence means that DBAs can’t manage a single set of technologies with a single set of tools. And modern applications are almost always distributed with clustering and replication across large numbers …

I am working on New features in Performance Schema 5.7 in action tutorial for Percona Live Amsterdam for quite a time already. Probably since version 5.7.3 when instrumentation for metadata locks were introduced and which I presented as a teaser in my combined "General MySQL Troubleshooting" and "Troubleshooting MySQL Performance" seminar I did in South Korea for Oracle University (for 5.6 that time).

In version 5.7.6 instrumentation for variables and status variables were introduced. It supports session, global and user variables. I was very happy to see this addition, especially because …

This Log Buffer Edition covers the top blog posts of the week from the Oracle, SQL Server and MySQL arenas.

Oracle:

• Momentum and activity regarding the Data Act is gathering steam, and off to a great start too. The Data Act directs the Office of Management and Budget (OMB) and the Department of the Treasury (Treasury) to establish government-wide financial reporting data standards by May 2015.
• RMS has a number of async queues for processing new item location, store add, warehouse add, item and po induction. We have seen rows stuck in the queues and needed to release the stuck AQ Jobs.
• We have a number of updates to partitioned tables that are run from within pl/sql …

As we all know, good DBAs are a dime a dozen. They’re easy to replace and the cost of replacing them in terms of lost productivity, downtime, recruiting, training, etc is minimal. You may even suspect that your DBA(s) aren’t very good since there is occasional downtime and people complain about the systems running too slowly. Firing people is icky so we’ve identified 8 great ways to encourage your DBA to leave.

8. Specialize Their Role

Nothing puts more pressure on a DBA to perform than being a specialist. A specialist is the only person who has access or knowledge to do something, which means everyone else is going to be coerced into learned helplessness and apathy. Oh, and the bystander effect will run rampant when something goes wrong. “I’m sure the DBA is working on that.”

Yep. You definitely want the DBA’s role to be specialized so they’re properly isolated and all the blame falls on them when …

As we all know, good DBAs are a dime a dozen. They’re easy to replace and the cost of replacing them in terms of lost productivity, downtime, recruiting, training, etc is minimal. You may even suspect that your DBA(s) aren’t very good since there is occasional downtime and people complain about the systems running too slowly. Firing people is icky so we’ve identified 8 great ways to encourage your DBA to leave.

8. Specialize Their Role

Nothing puts more pressure on a DBA to perform than being a specialist. A specialist is the only person who has access or knowledge to do something, which means everyone else is going to be coerced into learned helplessness and apathy. Oh, and the bystander effect will run rampant when something goes wrong. “I’m sure the DBA is working on that.”

Yep. You definitely want the DBA’s role to be specialized so they’re properly isolated and all the blame falls on them when …

Some years ago I posted an article about the code size in the MySQL Workbench project and talked a bit about the different subprojects and modules. At that time the project consisted of ~400K LOC (including third-party code) and already then the parser was the second biggest part with nearly a forth of the size of the entire project. This parser project back then used the yacc grammar from the MySQL server codebase and was our base for all parsing tasks in the product. Well, things have changed a lot since these days and this blog post discusses the current parsing infrastructure in MySQL Workbench.

We started looking into a more flexible way of creating our parser infrastructure. Especially the generation of lexer and parser from the grammar was a long …

Fri, 2015-08-14 09:34geoff_montee_g

Conservative in-order parallel replication is a great feature in MariaDB 10.0 that improves replication performance by using knowledge of group commit on the master to commit transactions in parallel on a slave. If slave_parallel_threads is greater than 0, then the SQL thread will instruct multiple worker threads to concurrently apply transactions that were committed in the same group commit on the master.

Conservative in-order parallel replication is a good alternative to out-of-order parallel replication …