批处理，往自己的邮箱发一封邮件，批处理采用异步的处理方式处理数据，最多可以处理5000万条数据

global with sharing class MerchandiseBatch implements Database.Batchable<sObject>,Database.Stateful{

    Integer queryCount = 0;

    String myEmailAddress = 'weizhen.zhao@pactera.com';

    global Database.QueryLocator start(database.BatchableContext bc){

        String query  = 'select Name from Merchandise__c';

        return Database.getQueryLocator(query);

    }

    global void execute (Database.BatchableContext bc,List<Merchandise__c> merchandiseList){

        for(Merchandise__c merchandise : merchandiseList){

            Decimal price = merchandise.Price__c;

            price += 1;

            queryCount +=1;

        }

        upsert merchandiseList;

    }

    global void finish(Database.BatchableContext bc){

        System.debug('query count: '+ queryCount);

        Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();

        email.setToAddresses(new String[]{myEmailAddress});

        email.setSubject('show count');//set subject

        email.setHtmlBody('query Count' + queryCount);

        Messaging.sendEmail(new Messaging.SingleEmailMessage[]{email});

    }

}

MerchandiseBatch merchandise = new MerchandiseBatch();

Id batchId = Database.executeBatch(merchandise);