To achieve this using Salesforce Batch Apex, you can follow these steps:

1. Create a custom object to store the record counts for each day.
2. Create a batch class that retrieves the record count for the given object and compares it with the previous day's count.
3. Schedule the batch class to run daily.

Here's an example of the code:

Custom Object:
1. Create a custom object Daily_Record_Count__c with the following fields:
 - Date__c (Date, unique): The date when the record count was taken.
 - Record_Count__c (Number): The number of records created on the given date.

Batch Class:
Create a batch class that implements the Database.Batchable<sObject> and Database.Stateful interfaces.
 

global class RecordCountBatch implements Database.Batchable<sObject>, Database.Stateful {
    global Integer recordsToday = 0;
    global Integer recordsYesterday = 0;

    global Database.QueryLocator start(Database.BatchableContext bc) {
        Date today = Date.today();
        Date yesterday = today.addDays(-1);

        String query = 'SELECT Id, CreatedDate FROM YourCustomObject__c WHERE CreatedDate = TODAY OR CreatedDate = YESTERDAY';
        return Database.getQueryLocator(query);
    }

    global void execute(Database.BatchableContext bc, List<sObject> scope) {
        for(sObject s : scope) {
            YourCustomObject__c record = (YourCustomObject__c) s;
            Date createdDate = record.CreatedDate.date();
            if(createdDate == Date.today()) {
                recordsToday++;
            } else if(createdDate == Date.today().addDays(-1)) {
                recordsYesterday++;
            }
        }
    }

    global void finish(Database.BatchableContext bc) {
        if(recordsToday > recordsYesterday) {
            sendEmail(recordsToday, recordsYesterday);
        }
    }

    private void sendEmail(Integer recordsToday, Integer recordsYesterday) {
        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
        String[] toAddresses = new String[] {'your.email@example.com'};
        mail.setToAddresses(toAddresses);
        mail.setSubject('Record count comparison: Today vs Yesterday');
        mail.setPlainTextBody('Record count today: ' + recordsToday + '\nRecord count yesterday: ' + recordsYesterday);
        Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
    }
}

Replace YourCustomObject__c with the API name of the object you want to monitor.

Schedule the Batch Class: Schedule the batch class to run daily using the System.schedule method or through the Salesforce UI.
 

String cronExp = '0 0 0 * * ?'; // Run daily at midnight
String jobName = 'Daily Record Count Comparison';
RecordCountBatch rcBatch = new RecordCountBatch();
System.schedule(jobName, cronExp, rcBatch);

If you find this useful, kindly consider selecting it as the Best Answer.

Thank you.
Divya Agrawal