Hanging out in #mysql on freenode the other day, I overheard someone saying that the reason to use connection pools with MySQL is because JDBC connections are expensive to create. That is true out of the box, but mostly because the out of the box behavior of MySQL's JDBC driver is to be standards-compliant. If you know that your DBA and your developers aren't doing crazy things with the database (changing configurations without letting the developers know, going around the "standard" API calls to start/end transactions, etc), then you can get to the point where connection setup is no slower than any other API. Does this mean you shouldn't use a connection pool? NO! (more on this next week).

Here's an iterative overview of the changes made in configuration, and how they affect what queries the driver does on initialization.

First, asking the

If you're using Innodb and transactions with JDBC and your MySQL application, you should know about a couple of debugging features that made their way into MySQL Connector/J 5.1.15.

First, by adding "includeThreadNamesAsStatementComment=true" to your JDBC URL, you will get the current Java thread's name that is executing SQL on a given connection as a statement comment, visible in SHOW FULL PROCESSLIST output:

mysql> show full processlist;
+------+------+-----------------+------+---------+------+----------+------------------------------------------------------+
| Id   | User | Host            | db   | Command | Time | State    | Info                                                 |
+------+------+-----------------+------+---------+------+----------+------------------------------------------------------+
...

Three great beta deliveries in one week!

MySQL Connector/.Net 6.0.2 beta, a new version of the all-managed .NET driver for MySQL.

MySQL Connector/C++ 1.0.4 beta, a new release providing  C++ API for connecting client applications to the MySQL Server. If you know JDBC, this should be familiar to you.

MySQL Connector/C 6.0.0 beta, a new version of the C API for accessing MySQL database servers

Use them and let us know what you think.

Learn more about Connector/C++

Three great beta deliveries in one week!

MySQL Connector/.Net 6.0.2 beta, a new version of the all-managed .NET driver for MySQL.

MySQL Connector/C++ 1.0.4 beta, a new release providing  C++ API for connecting client applications to the MySQL Server. If you know JDBC, this should be familiar to you.

MySQL Connector/C 6.0.0 beta, a new version of the C API for accessing MySQL database servers

Use them and let us know what you think.

Learn more about Connector/C++

Three great beta deliveries in one week!

MySQL Connector/.Net 6.0.2 beta, a new version of the all-managed .NET driver for MySQL.

MySQL Connector/C++ 1.0.4 beta, a new release providing  C++ API for connecting client applications to the MySQL Server. If you know JDBC, this should be familiar to you.

MySQL Connector/C 6.0.0 beta, a new version of the C API for accessing MySQL database servers

Use them and let us know what you think.

Learn more about Connector/C++

A new technical article entitled "Using the MySQL Connector/J JDBC Driver With the Java SE Platform", has been posted on java.sun.com at:

        http://java.sun.com/developer/technicalArticles/mysql_java/index.html

This article explains the essential steps involved in accessing/manipulating the data in a MySQL database from a Java application. MySQL Connector/J JDBC driver was used in the example code to show the database connectivity, data manipulation steps. Application developers who are new to Java programming language [but not to MySQL database] are the target audience of this article.

Stay tuned for the next article in this series "Using MySQL with PHP" ..

A new technical article entitled "Using the MySQL Connector/J JDBC Driver With the Java SE Platform", has been posted on java.sun.com at:

        http://java.sun.com/developer/technicalArticles/mysql_java/index.html

This article explains the essential steps involved in accessing/manipulating the data in a MySQL database from a Java application. MySQL Connector/J JDBC driver was used in the example code to show the database connectivity, data manipulation steps. Application developers who are new to Java programming language [but not to MySQL database] are the target audience of this article.

Stay tuned for the next article in this series "Using MySQL with PHP" ..

A new technical article entitled "Using the MySQL Connector/J JDBC Driver With the Java SE Platform", has been posted on java.sun.com at:

        http://java.sun.com/developer/technicalArticles/mysql_java/index.html

This article explains the essential steps involved in accessing/manipulating the data in a MySQL database from a Java application. MySQL Connector/J JDBC driver was used in the example code to show the database connectivity, data manipulation steps. Application developers who are new to Java programming language [but not to MySQL database] are the target audience of this article.

Stay tuned for the next article in this series "Using MySQL with PHP" ..

• No need to create a new database connection for each Rails instance.
• No need to specify your password in database.yml or create a hack to hide it.
• No garbage collection of connection after each use.

Using the instructions followed in JRuby Hack Day and taking some help from Nick, I figured out how to use the JDBC connection pools configured in GlassFish using the JNDI names.

All the commands given below are relevant for GlassFish but the same concept will work where ever you deploy your WARed up JRuby on Rails application.