I have a problem with an easy way to install MySQL via rpm without resorting to specifying the exact point release of MySQL. Presently my local yum repository has versions of 5.0, 5.1,5.4 and 5.5.

If I want to install MySQL Sever, I can just run:

$ sudo yum install -y MySQL-server
Setting up Install Process
Package MySQL-server-community-5.5.0-1.rhel5.x86_64 already installed and latest version
Nothing to do

The issue here is the most current version is installed. If I want to install the most current version of 5.1 for example, I have found no way to specify MySQL-server-5.1, or MySQL-server-community-5.1, I have to specify the point release MySQL-server-community-5.1.40

I suspect there is some internal aliasing that may be possible within rpm’s to support this. I’m seeking help from any rpm experts and would appreciate any feedback.

My current products include:

$ sudo yum list …

Many providers embedd MySQL with their commercial products including Adobe, Macfee, Nokia, Symantec and ScienceLogic just to name a few. In addition most commercial third party storage engines have for years been forced to provided very customized versions of MySQL due to limitations in the storage engine API. These situations require a license agreement necessary with the trademark holder of MySQL. The Oracle Corporation EU Statement released on December 14, 2009 has carefully worded in the statement about these OEM licenses and storage engine providers there will be no changes for 5 years.

One specific detail is missing, what happens then?

As an individual that uses, recommends, promotes and advises clients especially on various storage engine …

As part of reviewing storage engines for my work on the upcoming Expert PHP and MySQL book, I finally had an excuse to try out the InnoDB Plugin for MySQL which is now conveniently included with MySQL 5.1 since 5.1.38.

Following the MySQL 5.1 Reference Manual instructions at 13.6. The InnoDB Storage Engine I included the bare minimum as documented to my my.cnf.

[mysqld]
ignore-builtin-innodb
plugin-load=innodb=ha_innodb_plugin.so ;innodb_trx=ha_innodb_plugin.so ;innodb_locks=ha_innodb_plugin.so ;innodb_cmp=ha_innodb_plugin.so ;innodb_cmp_reset=ha_innodb_plugin.so ;innodb_cmpmem=ha_innodb_plugin.so ;innodb_cmpmem_reset=ha_innodb_plugin.so

However to my misfortune the following error occured.

091212 17:45:14 [ERROR] Can't open shared library …

One of the many cool new features in Java EE 6, is support for the DataSourceDefinition annotation.

The DataSourceDefinition annotation provides a way to define a DataSource and register it with JNDI. The annotation provided annotation elements for the commonly used DataSource properties. Additional standard and vendor specific properties may also be specified.

So let us look at an example:

@DataSourceDefinition(name = "java:global/MyApp/myDS",

className = "org.apache.derby.jdbc.ClientDataSource",

portNumber = 1527,

serverName = "localhost",

databaseName = "testDB",

user = "lance",

password = "secret",

properties = {"createDatabase=create"}) )

The data source will be registered using the value specified in the name element and can be defined in any valid Java EE name space and that will determine the accessibility of the data …

One of the many cool new features in Java EE 6, is support for the DataSourceDefinition annotation.

The DataSourceDefinition annotation provides a way to define a DataSource and register it with JNDI. The annotation provided annotation elements for the commonly used DataSource properties. Additional standard and vendor specific properties may also be specified.

So let us look at an example:

@DataSourceDefinition(name = "java:global/MyApp/myDS",
className = "org.apache.derby.jdbc.ClientDataSource",
portNumber = 1527,
serverName = "localhost",
databaseName = "testDB",
user = "lance",
password = "secret",
properties = {"createDatabase=create"}) )

The data source will be registered using the value specified in the name element and can be defined in any valid Java EE name space and that will determine the accessibility of the data source from other …

One of the many cool new features in Java EE 6, is support for the DataSourceDefinition annotation.

The DataSourceDefinition annotation provides a way to define a DataSource and register it with JNDI. The annotation provided annotation elements for the commonly used DataSource properties. Additional standard and vendor specific properties may also be specified.

So let us look at an example:

@DataSourceDefinition(name = "java:global/MyApp/myDS",

className = "org.apache.derby.jdbc.ClientDataSource",

portNumber = 1527,

serverName = "localhost",

databaseName = "testDB",

user = "lance",

password = "secret",

properties = {"createDatabase=create"}) )

The data source will be registered using the value specified in the name element and can be defined in any valid Java EE name space and that will determine the accessibility of the data …

A MySQL is running happily on a machine situated in a land far far away. I grant access to a user@machine_aaaaaa (grant select on db.* to ‘user’@'machine_aaaaa’ identified by ‘password’; flush privileges;), send an email to the user saying it should run fine and happily go off my way. Mistake!

It seems this user can’t connect to the mysql gets access denied:
Access denied for user ‘user’@'machine_bbbbb’ (using password: YES)

Note that the machine the user is being seen from is totally different from the one I set up in the grant!! WHY?

run a reverse lookup on the ip of machine_aaaaa, turns out it shows machine_bbbbb. So I figure a big bad guy messed up /etc/hosts, I was right! `cat /etc/hosts` just to find an entry for machine_aaaaa blehh

Ok, solution is to remove the entry from /etc/hosts (after finding out it wasn’t even necessary and wasn’t even supposed to be there in the first …

WIKIPEDIA -

Irony (from the Ancient Greek εἰρωνεία eirōneía, meaning hypocrisy, deception, or feigned ignorance) is a situation, literary technique or rhetorical device, in which there is an incongruity, discordance or unintended connection that goes beyond the most evident meaning. It is the expression of one’s meaning by using language that normally signifies the opposite.

Types of irony
Modern theories of rhetoric distinguish among verbal, dramatic and situational irony.
▪ Verbal irony is a disparity of expression and intention: when a speaker says one thing but means another, or when a literal meaning is contrary to its intended effect. An example of this is sarcasm.
▪ Dramatic irony is a disparity of expression and awareness: when words and actions possess a significance that the listener or audience understands, but the speaker or character does not.
▪ Situational irony …

MySQL instance running an Infobright engine


mysql> explain SELECT COUNT(ac.UID) FROM ACTIVE ac JOIN ALL a;
+----+-------------+-------+------+---------------+------+---------+------+---------+-------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+------+---------+------+---------+-------+
| 1 | SIMPLE | ac | ALL | NULL | NULL | NULL | NULL | 124426 | |
| 1 | SIMPLE | a | ALL | NULL | NULL | NULL | NULL | 7594256 | |
+----+-------------+-------+------+---------------+------+---------+------+---------+-------+
2 rows in set (0.01 sec)

mysql> SELECT COUNT(ac.UID) FROM ACTIVE ac JOIN ALL a ON ac.UID=a.UID;
+---------------+
| COUNT(ac.UID) |
+---------------+
| 17466 |
+---------------+
1 row in set (0.23 sec)

…

If you have more then a single MySQL database for your production environment, e.g. a development and test environment, or a MySQL replication topology, ensuring your schema’s are in sync can be task that requires some time if not managed correctly.

There is a tool I do use for MySQL environments called Schema Sync – a MySQL Schema Versioning and Migration Utility. There are many reasons why schema’s get out of sync. Developers may not ensure their changes are reflected in any software to be deployed, and when not tested you could end up with broken functionality. A DBA might try some different index strategies on a slave, but not the master, and never implement or revert.

While some people want the quick and hidden just sync version akin to Rails, I really like this product as it produces proper patch and revert SQL scripts. As a DBA I really want to know what’s going to …