Effect in application performance by Repository pattern and Unit of work with entity framework in asp.net mvc

Question

I am working with a database where I have more than 75 tables and I am using the repository and unit of work patterns with Entity Framework in an ASP.NET MVC project. I am little bit confused and some query in my mind about object creation. When UnitOfWork initializes, it creates object for all table's entity which is present in UnitOfWork. So it can be heavy for application load.

Here is the interface of unit of work:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Application.Repository;
using Application.Repository.General;

namespace Application.UnitOfWorks
{
    public interface IUnitOfWork : IDisposable
    {
        IGeneralRegionMasterRepository GeneralRegionMasters { get; }
        IGeneralSubRegionMasterRepository GeneralSubRegionMasters { get; }
        IGeneralCountryMasterRepository GeneralCountryMasters { get; }
        IGeneralStateMasterRepository GeneralStateMasters { get; }
        IGeneralCityMasterRepository GeneralCityMasters { get; }

        int Complete();
    }
}

Implementation:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Application.EntityFramework;
using Application.Repository;
using Application.Repository.General;

namespace Application.UnitOfWorks
{
    public class UnitOfWork : IUnitOfWork
    {
        public readonly InventoryDbContext _context;
        public UnitOfWork(InventoryDbContext context)
        {
            _context = context;
            GeneralRegionMasters = new GeneralRegionMasterRepository(_context);
            GeneralSubRegionMasters = new GeneralSubRegionMasterRepository(_context);
            GeneralCountryMasters = new GeneralCountryMasterRepository(_context);
            GeneralStateMasters = new GeneralStateMasterRepository(_context);
            GeneralCityMasters = new GeneralCityMasterRepository(_context);
        }

        public IGeneralRegionMasterRepository GeneralRegionMasters { get; private set; }
        public IGeneralSubRegionMasterRepository GeneralSubRegionMasters { get; private set; }
        public IGeneralCountryMasterRepository GeneralCountryMasters { get; private set; }
        public IGeneralStateMasterRepository GeneralStateMasters { get; private set; }
        public IGeneralCityMasterRepository GeneralCityMasters { get; private set; }

        public int Complete()
        {
            return _context.SaveChanges();
        }

        public void Dispose()
        {
            _context.Dispose();
        }
    }
}

I want to know about performance effect of it on application. Thank you in advance for help.

Answer 1

Re:

When UnitOfWork initializes, it creates object for all table's entity which is present in UnitOfWork. So it can be heavy for application load.

You don't need to initialize all the repo instances in the UoW constructor. You can create them when they are required in the corresponding getters (lazy initialization):

private IGeneralRegionMasterRepository _generalRegionMasters;
public IGeneralRegionMasterRepository GeneralRegionMasters {
  get {
    if (_generalRegionMasters == null) {
      _generalRegionMasters = new GeneralRegionMasterRepository(_context);
    }
    return _generalRegionMasters;
  }
}