Wouldn’t it be nice if you could get expert advice on your SQL queries to find problems in them, the same way that programmers can use lint-check tools to warn about bugs in their C?

if ( execute = 1 ) {
   launch_missile();
}

Such a simple mistake, but it’s the kind of thing that James Bond movies are made of, isn’t it? Well, a lot of SQL queries have similar bugs, and thanks to Miguel Trias, now there’s a tool to help you find them. This is the second addition to our online suite of tools for MySQL users. You paste a query, it tells you what’s wrong with it. Simple as that.

Find the bug in this query:

select * from t1
   left join t2 using(id)
where t2.created_date < 2012-02-15;

Do you see it? Congratulations! I've analyzed that query with the tool, and shared the results with you. …

1 Billion queries per minute with MySQL Cluster

Oracle announced the General Availability of MySQL Cluster 7.2 today. Join this live webinar to learn about what’s new in the production-ready, GA release of MySQL Cluster 7.2, enabling the latest generation of web and telecoms applications to take advantage of high write scalability, SQL and NoSQL interfaces and 99.999% availability, including:

• Performance enhancements delivering 1 billion queries per minute, using just 8 data nodes
• 70x higher JOIN performance with Adaptive Query Localization, enabling real-time analytics across live data sets
• New NoSQL API via Memcached, creating a persistent, key-value datastore for schema and schemaless data
• Auto-sharding across data centers with synchronous replication for scaling …

Want a free copy of High Performance MySQL, Third Edition? If you register before the early-bird pricing expires for the MySQL Conference in April, and use the discount code PL-Book, you’ll get to take a free copy home from the conference!

And now, a status update: I’m currently proofing the QC2 (quality control #2) revision of the book; after this, the book goes to manufacturing. The PDF is now 820 pages, which is a lot of work to proofread. You can imagine how much more in-depth we’ve been able to go with so many more pages.

The free sample online is …

MySQL Connector/Net 6.5.2, a new version of the all-managed .NET driver for MySQL has been released.  This is the first of our two Release Candidate (RC) releases.  As is the case with all non-GA releases, it should not be used in any production environment.  It is appropriate for use with MySQL server versions 5.0-5.6

It is now available in source and binary form from http://dev.mysql.com/downloads/connector/net/#downloads and mirror sites (note that not all mirror sites may be up to date at this point-if you can't find this version on some mirror, please try again later or choose another download site.)

The 6.5 release of MySQL Connector/Net brings new features such as

• Exception and command injector support
• Millseconds support
• Better partial-trust support …

70x Higher JOIN Performance, NoSQL Key-Value API & Cross Data Center Sharding with Synchronous Replication 

Oracle is delighted to announce the immediate availability of the production-ready, GA release of MySQL Cluster 7.2, available for download under the GPL, and as part of the commercial MySQL Cluster Carrier Grade Edition, including management tools, product certifications and 24x7 global support.

1 Billion Queries per Minute

MySQL Cluster delivered 1 billion queries per minute (17.6m million queries per second), scaled-out across 8x commodity Intel x86 server nodes, accessed by the NoSQL C++ NDB API.

It …

1 Billion queries per minute with MySQL Cluster

Oracle have just announced that MySQL Cluster 7.2 is now GA and available for production deployments.

Amongst the highlights for the release are:

• Performance enhancements delivering 1 billion queries per minute, using just 8 data nodes
• 70x higher JOIN performance with Adaptive Query Localization, enabling real-time analytics across live data sets
• New NoSQL API via Memcached, creating a persistent, key-value datastore for schema and schemaless data
• Auto-sharding across data centers with synchronous replication for scaling of highly available, global services
• Simplified ease-of-use with new options for on-premise and cloud …

MySQL Cluster Manager 1.1. is now available to download and try from Oracle E-Delivery (select “MySQL Database” as the product pack).

There’s lots of good stuff gone in under the covers as part of this release, with some of the highlights being:

• Support for MySQL Cluster 7.2
• Configuration of MySQL Server parameters
• Verbose option added to commands for extra info on what’s going on
• Faster Cluster rolling restarts – data nodes from different node groups will be restarted in parallel (still avoids an outage but cuts the end-to-end restart time)
• Robustness enhancements to the configurator – especially important when managing large Clusters
• Bug fixes (well we always need to include that one) …

Memcached API with Cluster Data Nodes

The native Memcached API for MySQL Cluster is now GA as part of MySQL Cluster 7.2

This post was first published in April 2011 when the first trial version of the Memcached API for MySQL Cluster was released; it was then up-versioned for the second MySQL Cluster 7.2 Development Milestone Release in October 2011. I’ve now refreshed the post based on the GA of MySQL Cluster 7.2 which includes the completed Memcache API.

There are a number of attributes of MySQL Cluster that make it ideal for lots of applications that are considering NoSQL data stores. Scaling out capacity and performance on commodity hardware, in-memory real-time performance (especially for simple access patterns), flexible schemas… sound familiar? In addition, MySQL …

For MySQL Cluster 7.2 we have worked on increasing the number of CPUs that can be used to execute the workload on the data nodes.

A MySQL Cluster 7.2 data node is functionally divided into 7 thread types.

1) The Local Data Manager threads (ldm)
2) The Transaction Coordinator threads (tc)
3) The Asynchronous Replication threads (rep)
4) The Schema Management threads (main)
5) Network receiver threads (recv)
6) Network send threads (send)
7) IO threads

In the LDM domain we have increased the maximum number of threads from 4 to 16. The LDM contains the actual data, this means that when using 16 threads the data becomes more partitioned (as usual this is all automatic in MySQL Cluster). Each LDM thread maintains its own set of data partitions, index partitions and its own REDO log. The number of LDM parts per data node isn't dynamically changeable. It's however …

We've passed another performance milestone using MySQL Cluster. In 2002 we passed the limit of 1M reads per second. Now we've passed the milestone of 1B reads per minute. We achieved 1.05BN reads per minute on an 8-node cluster using MySQL Cluster 7.2.5.

The benchmark used the latest MySQL Cluster version, available on launchpad and to be released as MySQL Cluster 7.2.5. The benchmark program is flexAsynch. Each read is a transaction consisting of a read of an entire row consisting of 25 attributes, each 4 bytes in size. flexAsynch uses the asynchronous feature of the NDB API which enables one thread to send off multiple transactions in parallel. This is handled similarly to how Node.js works with callbacks registered that reports back when a transaction is completed.

I will in a later blog discuss how an application can be designed to make optimal use of the asynchronous API to enable the application to reach these …