.Net Core 3.1 Entity Framework Slow Query Problem - asp.net-core

Question

There was slowness in my .net core webapi application, I reviewed and redesigned my queries to resolve this issue. The code snippet below was written to bring in sales, payments for sales, and sales territories.
I first include the condition query and then the sub-entities in the query. Then I choose which columns to work with ".Select()".
Then I want to combine this table with the name information in other tables. For example, information such as Customer Name, Product Name is in the other table.
The first block of code I share below is a slow running linq query.
result.Results =
(from s in context.Sales
join sa in context.SaleProductServiceAreas on s.SaleId equals sa.SaleId
join sp in context.SalePayments on s.SaleId equals sp.SaleId into spleft
from sp in spleft.DefaultIfEmpty()
join c in context.Customers on s.CustomerId equals c.CustomerId
join p in context.ProductServices on s.ProductServiceId equals p.ProductServiceId
where s.Date >= firstDayOfMonth && s.Date <= lastDayOfMonth
group s by
new
{
s.SaleId,
s.CustomerId,
CustomerNameSurname = c.Name + ' ' + c.Surname,
ProductServiceName = p.Name,
s.Date,
s.Total,
s.Session,
p.ProductServiceId
} into grp
select new SaleJoinDto()
{
SaleId = grp.Key.SaleId,
CustomerNameSurname = grp.Key.CustomerNameSurname,
ProductServiceName = grp.Key.ProductServiceName,
Total = grp.Key.Total,
Date = grp.Key.Date,
Session = grp.Key.Session,
CustomerId = grp.Key.CustomerId,
ProductServiceId = grp.Key.ProductServiceId,
SaleProductServiceAreas = (from sps in context.SaleProductServiceAreas
join spa in context.ProductServiceAreas on sps.ProductServiceAreaId equals spa.ProductServiceAreaId
where sps.SaleId == grp.Key.SaleId
select new SaleProductServiceAreaJoinDto()
{
SaleProductServiceAreaId = sps.SaleProductServiceAreaId,
ProductServiceAreaName = spa.Name,
ProductServiceAreaId = sps.ProductServiceAreaId,
SaleId = sps.SaleId
}).ToList(),
SalePayments = (from spp in context.SalePayments
where spp.SaleId == grp.Key.SaleId
select new SalePaymentDto()
{
SaleId = spp.SaleId,
SalePaymentId = spp.SalePaymentId,
Total = spp.Total,
PaymentMethod = spp.PaymentMethod,
Date = spp.Date
}).ToList()
}).ToList();
["NEW"] This query I wrote is the query I rewrite as a result of the articles I have shared below.
Document of Microsoft Link for query
using (var context = new AppDbContext())
{
var result = new PagedResult<SaleJoinDto>();
result.CurrentPage = pageNumber;
result.PageSize = pageSize;
var pageCount = (double)result.RowCount / pageSize;
result.PageCount = (int)Math.Ceiling(pageCount);
var skip = (pageNumber - 1) * pageSize;
var firstDayOfMonth = new DateTime(date.Year, date.Month, 1);
var lastDayOfMonth = firstDayOfMonth.AddMonths(1).AddDays(-1);
result.Results = await context.Sales
.Where(x => x.Date >= firstDayOfMonth && x.Date <= lastDayOfMonth)
.Include(x => x.SalePayments)
.Include(x => x.SaleProductServiceAreas)
.Select(s => new Sale()
{
SaleId = s.SaleId,
CustomerId = s.CustomerId,
Date = s.Date,
Total = s.Total,
Session = s.Session,
SalePayments = s.SalePayments,
SaleProductServiceAreas = s.SaleProductServiceAreas
})
.Join(context.Customers, sales => sales.CustomerId, customers => customers.CustomerId, (sales, customers) => new
{
sales,
customers
})
.Join(context.ProductServices, combinedSaleAndCus => combinedSaleAndCus.sales.ProductServiceId, product => product.ProductServiceId, (combinedSaleAndCus, product) => new SaleJoinDto()
{
SaleId = combinedSaleAndCus.sales.SaleId,
CustomerId = combinedSaleAndCus.sales.CustomerId,
Date = combinedSaleAndCus.sales.Date,
Total = combinedSaleAndCus.sales.Total,
Session = combinedSaleAndCus.sales.Session,
CustomerNameSurname = combinedSaleAndCus.customers.Name,
SalePayments = combinedSaleAndCus.sales.SalePayments.Select(x => new SalePaymentDto()
{
Date = x.Date,
PaymentMethod = x.PaymentMethod,
SaleId = x.SaleId,
SalePaymentId = x.SalePaymentId,
Total = x.Total
}).ToList(),
SaleProductServiceAreas = combinedSaleAndCus.sales.SaleProductServiceAreas.Join(context.ProductServiceAreas, sp => sp.ProductServiceAreaId, psa => psa.ProductServiceAreaId, (sp, psa) => new SaleProductServiceAreaJoinDto()
{
SaleProductServiceAreaId = sp.SaleProductServiceAreaId,
ProductServiceAreaName = psa.Name
}).ToList()
})
.ToListAsync();
result.RowCount = result.Results.Count();
result.Results = result.Results.OrderByDescending(x => x.Date).Skip(skip).Take(pageSize).ToList();
return result;
}
The problem is I do get the following error when I rewrite it according to this new query.
Where am I making a mistake in the query I just wrote?
{"The LINQ expression 'DbSet\r\n .Where(s => s.Date >=
__firstDayOfMonth_0 && s.Date <= __lastDayOfMonth_1)\r\n .Join(\r\n outer: DbSet, \r\n inner: s => s.CustomerId, \r\n
outerKeySelector: c => c.CustomerId, \r\n innerKeySelector: (s,
c) => new TransparentIdentifier<Sale, Customer>(\r\n Outer
= s, \r\n Inner = c\r\n ))\r\n .Join(\r\n outer: DbSet, \r\n inner: ti => new Sale{ \r\n
SaleId = ti.Outer.SaleId, \r\n CustomerId =
ti.Outer.CustomerId, \r\n Date = ti.Outer.Date, \r\n
Total = ti.Outer.Total, \r\n Session = ti.Outer.Session,
\r\n SalePayments = (MaterializeCollectionNavigation(\r\n
navigation: Navigation: Sale.SalePayments,\r\n
subquery: DbSet\r\n .Where(s0 =>
EF.Property(ti.Outer, "SaleId") != null &&
EF.Property(ti.Outer, "SaleId") == EF.Property(s0,
"SaleId"))), \r\n SaleProductServiceAreas =
(MaterializeCollectionNavigation(\r\n navigation:
Navigation: Sale.SaleProductServiceAreas,\r\n subquery:
DbSet\r\n .Where(s1 =>
EF.Property(ti.Outer, "SaleId") != null &&
EF.Property(ti.Outer, "SaleId") == EF.Property(s1,
"SaleId"))) \r\n }\r\n .ProductServiceId, \r\n
outerKeySelector: p => p.ProductServiceId, \r\n
innerKeySelector: (ti, p) => new
TransparentIdentifier<TransparentIdentifier<Sale, Customer>,
ProductService>(\r\n Outer = ti, \r\n Inner =
p\r\n ))'
could not be translated. Either rewrite the query in
a form that can be translated, or switch to client evaluation
explicitly by inserting a call to either AsEnumerable(),
AsAsyncEnumerable(), ToList(), or ToListAsync(). See
https://go.microsoft.com/fwlink/?linkid=2101038 for more
information."}

Answer 1

Removed not needed joins and grouping. It should be faster.
var query =
from s in context.Sales
join c in context.Customers on s.CustomerId equals c.CustomerId
join p in context.ProductServices on s.ProductServiceId equals p.ProductServiceId
where s.Date >= firstDayOfMonth && s.Date <= lastDayOfMonth
select new SaleJoinDto()
{
SaleId = s.SaleId,
CustomerNameSurname = c.Name + ' ' + c.Surname,
ProductServiceName = p.ProductServiceName,
Total = s.Total,
Date = s.Date,
Session = s.Session,
CustomerId = s.CustomerId,
ProductServiceId = p.ProductServiceId,
SaleProductServiceAreas = (from sps in context.SaleProductServiceAreas
join spa in context.ProductServiceAreas on sps.ProductServiceAreaId equals spa.ProductServiceAreaId
where sps.SaleId == s.SaleId
select new SaleProductServiceAreaJoinDto()
{
SaleProductServiceAreaId = sps.SaleProductServiceAreaId,
ProductServiceAreaName = spa.Name,
ProductServiceAreaId = sps.ProductServiceAreaId,
SaleId = sps.SaleId
}).ToList(),
SalePayments = (from spp in context.SalePayments
where spp.SaleId == s.SaleId
select new SalePaymentDto()
{
SaleId = spp.SaleId,
SalePaymentId = spp.SalePaymentId,
Total = spp.Total,
PaymentMethod = spp.PaymentMethod,
Date = spp.Date
}).ToList()
};
result.Results = query.ToList();
Anyway, even joins can be simplified if you have navigation properties which are not shown in original question.

Answer 2

I fixed the slow responsiveness of the app.
I was running the application on windows host. I changed my hosting to Centos 7 which is a linux distribution. Then when I run the application on Centos 7, the application accelerated perfectly and took flight.
My advice to all .net Core app developers, migrate your apps to linux. It is built to run on .net core linux distributions.
I share the problems I encountered while migrating the application to linux and how I solved it in the link below.
.Net Core 3.1 deploy on Centos 7