wiki.techinc.nl/maintenance/initEditCount.php

<?php
/**
 * @file
 * @ingroup Maintenance
 */

require_once "commandLine.inc";

if( isset( $options['help'] ) ) {
	die( "Batch-recalculate user_editcount fields from the revision table.
Options:
  --quick        Force the update to be done in a single query.
  --background   Force replication-friendly mode; may be inefficient but
                 avoids locking tables or lagging slaves with large updates;
                 calculates counts on a slave if possible.

Background mode will be automatically used if the server is MySQL 4.0
(which does not support subqueries) or if multiple servers are listed
in \$wgDBservers, usually indicating a replication environment.

");
}
$dbw = wfGetDB( DB_MASTER );
$user = $dbw->tableName( 'user' );
$revision = $dbw->tableName( 'revision' );

$dbver = $dbw->getServerVersion();

// Autodetect mode...
$backgroundMode = count( $wgDBservers ) > 1 ||
	($dbw instanceof DatabaseMySql && version_compare( $dbver, '4.1' ) < 0);

if( isset( $options['background'] ) ) {
	$backgroundMode = true;
} elseif( isset( $options['quick'] ) ) {
	$backgroundMode = false;
}

if( $backgroundMode ) {
	echo "Using replication-friendly background mode...\n";
	
	$dbr = wfGetDB( DB_SLAVE );
	$chunkSize = 100;
	$lastUser = $dbr->selectField( 'user', 'MAX(user_id)', '', __FUNCTION__ );
	
	$start = microtime( true );
	$migrated = 0;
	for( $min = 0; $min <= $lastUser; $min += $chunkSize ) {
		$max = $min + $chunkSize;
		$result = $dbr->query(
			"SELECT
				user_id,
				COUNT(rev_user) AS user_editcount
			FROM $user
			LEFT OUTER JOIN $revision ON user_id=rev_user
			WHERE user_id > $min AND user_id <= $max
			GROUP BY user_id",
			__FUNCTION__ );
		
		while( $row = $dbr->fetchObject( $result ) ) {
			$dbw->update( 'user',
				array( 'user_editcount' => $row->user_editcount ),
				array( 'user_id' => $row->user_id ),
				__FUNCTION__ );
			++$migrated;
		}
		$dbr->freeResult( $result );
		
		$delta = microtime( true ) - $start;
		$rate = ($delta == 0.0) ? 0.0 : $migrated / $delta;
		printf( "%s %d (%0.1f%%) done in %0.1f secs (%0.3f accounts/sec).\n",
			$wgDBname,
			$migrated,
			min( $max, $lastUser ) / $lastUser * 100.0,
			$delta,
			$rate );
		
		wfWaitForSlaves( 10 );
	}
} else {
	// Subselect should work on modern MySQLs etc
	echo "Using single-query mode...\n";
	$sql = "UPDATE $user SET user_editcount=(SELECT COUNT(*) FROM $revision WHERE rev_user=user_id)";
	$dbw->query( $sql );
}

echo "Done!\n";