Google has launched another performance centric service i.e. Page Speed Service. It seems to be the content delivery service which other CDNs are providing with a difference by doing some performance tuning i.e. concatenating CSS and some other tasks which are also performed by Google's mod_pagespeed. By providing this service, Google will always have updated content for its services like Google search and AdSense. Let's see how Google plan this service future.

MySQL recently fixed a known bug (I was not aware of this before) of OPTIMIZE TABLE (in MySQL Server 5.1.55, 5.5.9) in which OPTIMIZE TABLE statement was not preserving the AUTO_INCREMENT counter on OPTIMIZE TABLE operation.

Want to see yourself? Lets do it (code taken from the MySQL bug report)

CREATE TABLE a (a INTEGER PRIMARY KEY NOT NULL AUTO_INCREMENT) ENGINE=INNODB;
 
INSERT INTO a VALUES ();
INSERT INTO a VALUES ();
INSERT INTO a VALUES ();
 
DELETE FROM a ;
 
SHOW TABLE STATUS LIKE 'a';

In the below table status, you can see the AUTO_INCREMENT value is 4 (even after deleting all the rows which is normal behavior).

mysql> SHOW TABLE STATUS LIKE 'a'\G
*************************** 1. row ***************************
           Name: a
         Engine: InnoDB
        Version: 10
     Row_format: Compact
           Rows: 3
 Avg_row_length: 5461
    Data_length: 16384
Max_data_length: 0
   Index_length: 0
      Data_free: 4194304
 Auto_increment: 4
    Create_time: 2011-02-20 07:52:18
    Update_time: NULL
     Check_time: NULL
      Collation: latin1_swedish_ci
       Checksum: NULL
 Create_options:
        Comment:
1 row in set (0.00 sec)

Now execute the OPTIMIZE TABLE command and check the table status

OPTIMIZE TABLE a;
 
SHOW TABLE STATUS LIKE 'a';

mysql> SHOW TABLE STATUS LIKE 'a'\G
*************************** 1. row ***************************
           Name: a
         Engine: InnoDB
        Version: 10
     Row_format: Compact
           Rows: 0
 Avg_row_length: 0
    Data_length: 16384
Max_data_length: 0
   Index_length: 0
      Data_free: 4194304
 Auto_increment: 1
    Create_time: 2011-02-20 07:52:18
    Update_time: NULL
     Check_time: NULL
      Collation: latin1_swedish_ci
       Checksum: NULL
 Create_options:
        Comment:
1 row in set (0.00 sec)

MySQL fixed this bug 5 years after the bug report.

So be careful with OPTIMIZE TABLE if you have older MySQL versions.

TRUNCATE TABLE reset the AUTO_INCREMENT to 1 so don't confuse this example with TRUNCATE TABLE.

I just attended MySQL webinar "What's New: MySQL 5.5 and MySQL Enterprise Edition". You may find the recording of this webinar at mysql.com. It was nice to see improved InnoDB performance (10x) as compared to MySQL 5.1 InnoDB. A couple of people in the webinar reported that they have experienced the enhanced performance with MySQL 5.5.

Here are some of the questions that looked interesting to me

Q: you have comparion charts between myisam and innodb?
A: We've just completed our MyISAM and InnoDB benchmarking and will be posting a whitepaper this week.

Q: Can you compare MySQL 5.5 partitioning schemas and performance with MS SQL Server 2008?
A: I'd recommend the following whitepaper for details: http://www.mysql.com/why-mysql/white-papers/mysql_wp_partitioning.php

Q: Are there any linux graphs/stats with using 2 or 4 core CPU's? The previous linux graphs were with 6 cores.
A: Here is a link to additional details regarding some of the benchmarks. Many of them start w/ 4 cores enabled and then expand to additional cores. As 2 cores scaled well with previous version, I believe most benchmarks started with 4 cores: http://assets.en.oreilly.com/1/event/36/What_s New in MySQL 5_5__ Performance and Scalability Benchmarks Presentation.pdf

Q: The white paper referenced for partitions is for 5.1. I am interested in the features and extensions that have been implemented in 5.5 A. Is there a newer white paper? Thanks
Q: Yes -- Here are improvements for 5.5 regarding partitioning http://dev.mysql.com/tech-resources/articles/mysql_55_partitioning.html

Q: Does MySQL support sub-partitioning ?
A: Yes http://dev.mysql.com/doc/refman/5.5/en/partitioning-subpartitions.html

Q: Is there any testing data available that focuses on the improved innodb performance in a virtual/cloud environment rather then the larger multi-core physical testing platforms noted in the presentation
A: I'd recommend reviewing the detailed presentation posted from our users conf: http://www.mysql.com/news-and-events/on-demand-webinars/display-od-532.html

Red Hat Enterprise Linux 5 and CentOS 5 are now shipping MySQL 5.0.77 instead of MySQL 5.0.45 on security grounds.

This is moderate security release according to RHEL and CentOS.

MySQL.com is conducting webinars on its usage in online applications. It is a series of 5 webinars i.e.

Part 1: Introduction to MySQL Scale Out and Replication Services
In the first installment we look at the basics for deploying MySQL for a scalable online application such as:

• Choosing the right architecture
• Scale Out - What, Why and How?
• Using MySQL Replication Services
• MySQL Solutions to help manage your high-growth business

North America -- Tuesday, August 18, 2009: 10:00 Pacific time / 1:00 Eastern time

EMEA -- Wednesday, August 26, 2009: 10:00 am European Central Time

The last release of PHP 4 is now available for download on 7th of August 2008. PHP 4 has been serving the web sites since 2000.