VividCortex now lets you search for queries that cause a specific error in your application. The error code itself will be database-specific, but for example error 1062 in MySQL is a duplicate key error, and in PostgreSQL error 23503 is a foreign key violation.

One of our customers requested that we add this feature so they could search for queries that cause UTF8 issues, which is a great example of when this can be useful.

To use this feature, click on the Queries navigation link, which brings up a catalog of every query we have seen execute in your systems. At the top, select the drop-down menu and filter by errors, then type in the error code you’re looking for and click Apply:

The result will be a listing of all queries that cause the server to return that error (even if it’s only an occasional error).

You might be surprised at how many queries cause once-in-a-million errors! They’re really hard to find …

Hi Keith 🙂

Thank you for the great write up. I am setting up a demo on raspberry pi 2, and the DemoKit you showed looks like fun. Please feel free to email me, if it is OK for me get a copy of DemoKit as well.

MySQL 5.5.45 was recently released (it is the latest MySQL 5.5, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.5.html

This release, similar to the last 5.5 release, is mostly uneventful.

There were 0 “Functionality Added or Changed” items this time, 1 “Security Fix”, and just 9 bugs overall fixed.

Out of the 9 bugs, there were 3 InnoDB bugs, 1 security-related bug, and 1 potential crashing bug. Here are the ones worth noting:

• InnoDB: An index record was not found on rollback due to inconsistencies in the purge_node_t structure.
• InnoDB: An assertion was raised when InnoDB attempted to dereference a NULL foreign key object.
• InnoDB: On Unix-like platforms, os_file_create_simple_no_error_handling_func and …

Introduction

A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table. The table containing the foreign key is called the child table, and the table containing the candidate key is called the referenced or parent table. The purpose of the foreign key is to identify a particular row of the referenced table. Therefore, it is required that the foreign key is equal to the candidate key in some row of the primary table, or else have no value (the NULL value). This is called a referential integrity constraint between the two tables. Because violations of these constraints can be the source of many database problems, most database management systems provide mechanisms to ensure that every non-null foreign key corresponds to a row of the referenced table. Consider following simple example:

create table parent (
    id int not null primary key,
    name char(80)
) …

Sun of database technologies is shining through the cloud technology. Oracle, SQL Server, MySQL and various other databases are bringing forth some nifty offerings and this Log Buffer Edition covers some of them.

Oracle:

• How to create your own Oracle database merge patch.
• Finally the work of a database designer will be recognized! Oracle has announced the Oracle Database Developer Choice Awards.
• Oracle Documents Cloud Service R4: Why You Should Seriously Consider It for Your Enterprise.
• Mixing Servers in a Server …

Today I released version 1.1 of myoradump for download from sourceforge. If you don't know what myoradump is, this is a utility for exporting data from an Oracle database in some relevant text format so that it can be imported to some other database.

The main thing in version 1.1 is that I have added a whole bunch of new output formats, so make it even easier to get your data out of expensive Oracle and into something more effective. The new formats supported are:

• MySQL - The format of this is a bunch of INSERT statements that you get when you use mysqldump for example and is useful for import into MariaDB (and MySQL). INSERT arrays are supported as a bunch of more options.
• JSON - This format is rather obvious, the output is a file consisting of one JSON object per row. To support binary …

During the last couple of months I have been involved in an unusually high amount of performance audits for e-commerce applications running with Magento. And although the systems were quite different, they also had one thing in common: the MySQL query cache was very useful. That was counter-intuitive for me as I’ve always expected the query cache to be such a bottleneck that response time is better when the query cache is turned off no matter what. That lead me to run a few experiments to better understand when the query cache can be helpful.

Some context

The query cache is well known for its contentions: a global mutex has to be acquired for any read or write operation, which means that any access is serialized. This was not an issue 15 years ago, but with today’s multi-core servers, such serialization is the best way to kill performance.

However from a performance …

VividCortex is sponsoring and exhibiting at PGConf Silicon Valley November 17 - 18th. Stop by our booth to get a free product demo and see how we can revolutionize your database monitoring.

Baron Schwartz will also be speaking on Analyzing PostgreSQL Network Traffic with vc-pgsql-sniffer, so be sure to learn from his experience.

Click here for more details and registration.

VividCortex is sponsoring and exhibiting at PGConf Silicon Valley November 17 - 18th. Stop by our booth to get a free product demo and see how we can revolutionize your database monitoring.

Baron Schwartz will also be speaking on Analyzing PostgreSQL Network Traffic with vc-pgsql-sniffer, so be sure to learn from his experience.

Click here for more details and registration.

If you run multiple MySQL instances on a Linux machine, chances are good that at one time or another, you’ve ended up connected to an instance other than what you had intended. It’s certainly happened to me, and I submitted Bug#76512 to deal with the cause which affects me most commonly – that the mysql client will silently ignore the –port option and connect using the default Unix socket instead when the host is “localhost” (default).  We’ve recently discussed ways we can make this behavior less surprising to users, and though we’re now past the second RC of MySQL Server 5.7, we’re contemplating making these changes in future 5.7 releases.  Please let us know your thoughts!

Here are the basic principles of what we intend to change:

Explicit –protocol option rules all

If a user provides an explicit …