Performance issues: Drupal 6.26 database versus Drupal 6.25 database InnoDB versus MyISAM

Drupal 7 is using InnoDB as default database engine. When you create a database in Drupal 6.26, it is already using the InnoDB engine for the database.
I had really performance issues running this database on my Ubuntu setup. It seems InnoDB has some trouble on my system to count the records in a table. Didn't do much investigating on this issue, because I had some deadlines coming up. Quick workaround: Change the database engine for all your tables back to MyISAM. Try this script (thanks to Danreb).

$dbServer // Database server, commonly use value is localhost
$dbUser// Database User, the one with priveleges to your database
$dbPass // Password of the Database User
$dbName // The database you want to convert from InnoDB to MyISAM

<?php
// display error is On for us to be notified if there's something wrong
ini_set('display_errors', 'On');
error_reporting(E_ALL);


// Config, change this variables
$dbServer = "localhost";
$dbUser = "root";
$dbPass = " ";
$dbName = "testdb";

// Set a connection for our database 
$link = mysql_connect($dbServer, $dbUser, $dbPass)
or die("unable to connect to msql server: " . mysql_error());

// Select our database
mysql_select_db($dbName, $link)
or die("unable to select database 'db': " . mysql_error());

$result = mysql_query("show tables");
if (!$result) {
  die('query failed: ');
}

// Use while loop to convert all tables to MyISAM
while ($row = mysql_fetch_array($result)){
// Command Reference: ALTER TABLE tableName ENGINE=MyISAM
mysql_query("ALTER TABLE ".$row[0]." ENGINE=MyISAM; ");
}

?>

You can run this php code using the 'Execute PHP code' link in your devel menu.