Create Bulk record

public class CreateBulkAccountsBatch implements Database.Batchable<Integer>, Database.Stateful {
    
    private Integer totalRecordsToCreate = 500000;
    private Integer recordsCreated = 0;
    private Integer batchSize = 10000;

    public Iterable<Integer> start(Database.BatchableContext bc) {
        List<Integer> chunks = new List<Integer>();
        Integer remainingRecords = Math.min(batchSize, totalRecordsToCreate - recordsCreated);
        
        for (Integer i = 0; i < remainingRecords; i += 200) {
            chunks.add(i);
        }
        
        return chunks;
    }
    
    public void execute(Database.BatchableContext bc, List<Integer> chunk) {
        List<Account> accountsToInsert = new List<Account>();
        Integer startIndex = chunk[0];
        Integer endIndex = Math.min(startIndex + 200, batchSize);
        
        for (Integer i = startIndex; i < endIndex; i++) {
            if (recordsCreated < totalRecordsToCreate) {
                Account acc = new Account(
                    Name = 'Bulk Account ' + (recordsCreated + 1),
                    Description = 'Created by batch process'
                );
                accountsToInsert.add(acc);
                recordsCreated++;
            }
        }
        
        if (!accountsToInsert.isEmpty()) {
            insert accountsToInsert;
        }
    }
    
    public void finish(Database.BatchableContext bc) {
        System.debug('Batch job completed. Total records created so far: ' + recordsCreated);
        
        if (recordsCreated < totalRecordsToCreate) {
            // Chain the next batch
            CreateBulkAccountsBatch nextBatch = new CreateBulkAccountsBatch();
            nextBatch.recordsCreated = this.recordsCreated;
            Database.executeBatch(nextBatch, 200);
        } else {
            System.debug('All ' + totalRecordsToCreate + ' records have been created.');
        }
    }
}