I use a stored procedure to fetch data and modifications from the database.
If i use LINQ for the same job will there be any performance issue? I mean will I get better performance or not?
I saw that LINQ syntax is bit complicated, so is there any tool which help me to generate LINQ syntax.
thanks
There is a slight performance impact against using Linq2Sql VS calling stored procedures; for one, the stored procedure can be compiled and stored so subsequent calls are quicker, and you have more control and options in T-SQL land VS having Linq2Sql generate the statements for you.
However, unless your site is getting heavy traffic, theres no reason not to use it if you are looking for an easy way to get your site set up.
In general, LINQ will not beat the performance of a stored procedure. After all, Linq2Sql generates SQL and that will never be better than a well-written stored procedure.
Linq2sql, if not used properly, can harm performance. That is often caused by developers that do not understand the deferred loading principle and that can lead to a LOT of queries.
Where it WILL create performance issues is with bulk operations. This is an area where you do not want to use Linq2Sql but you need SqlBulkCopy or stored procedures.
Nevertheless, I use it a lot and am happy in general.
LinqPad is a free program and can be a way to learn LINQ. It comes loaded with 500 examples.
Related
Can LINQ to Entities entirely replace ADO.Net technology?
What I really want to know is, Is it possible to achieve every features and functionality that ADO.Net provides by using LINQ ? Who is the Boss?
Since you said in your comment that you mean LINQ to Entities, I will answer thus:
LINQ to Entities internally use ADO.Net, so it would be impossible for LINQ to Entities to replace ADO.Net, because it uses it. However I am assuming that you mean to ask if you can use LINQ to Entities in every situation that you could use ADO.Net. The answer is no, you cannot.
There are cases that you would not want to (or could not) use LINQ to Entities. For example if you are in a certain situation where you need better performance for a query, it would be better to use a stored procedure. Generally LINQ to Entities is a better choice when developer productivity has a higher priority than the execution speed of queries. Other cases where LINQ to Entities is not a good choice is when a DB has been poorly designed and does not have a primary key for example.
But the main point I think is this: What has higher priority in your situation? Developer productivity or performance? It is also quite acceptable I think to use both technologies. Complete the project with LINQ to Entities, and if there are performance issues, use stored procedures or ADO.Net.
Also, I would not use LINQ to Entities for large queries, or queries that have many joins, LINQ syntax for joins is not very terse, and may hurt the readability of your code.
#Reddy, it entirely depends on the scenario where you are deciding which technology to use. ADO.NET gives you tuple structure using DataSet at its focus and is used even day compared to ORM like tech i.e. LINQ-Entity. I have refrained to ADO.NET when the prime aspect of the application revolves around record processing, used in the SSIS pipeline but have stuck to LINQ-Entity when I primarily follow Test Driven Development or Domain Driven Development approaches.
1)ADO.NET is the database connectivity technology, so we can use ado.net to do operations with only Databases , but if we get a requirement to get the data from non database datasources like xml,collections etc.. its not possible.
But using LINQ it is possible to get data from many datasources like collections, XML files, Entities, even with Databases also.
2) But if you come to the performance wise ADO.NET is very faster than any other database connective technologies.
3) If you go with LINQ Run time errors can be rectified so bugs will be less ,so reliability increases
so ADO.NET vs LINQ technologies both having their own positives and negative features ,Microsoft given huge amount of featured technologies, so according to the application requirement we need to go with that technology.
I have a problem. My LINQ to SQL queries are pushing data to the database at ~1000 rows per second. But this is much too slow for me. The objects are not complicated. CPU usage is <10% and bandwidth is not the bottleneck too.
10% is on client, on server is 0% or max 1% generally not working at all, not traversing indexes etc.
Why 1000/s are slow, i need something around 20000/s - 200000/s to solve my problem in other way i will get more data than i can calculate.
I dont using transaction but LINQ using, when i post for example milion objects new objects to DataContext and run SubmitChanges() then this is inserting in LINQ internal transaction.
I dont use parallel LINQ, i dont have many selects, mostly in this scenario i'm inserting objects and want use all resources i have not only 5% od cpu and 10kb/s of network!
when i post for example milion objects
Forget it. Linq2sql is not intended for such large batch updates/inserts.
The problem is that Linq2sql will execute a separate insert (or update) statement for each insert (update). This kind of behaviour is not suitable with such large numbers.
For inserts you should look into SqlBulkCopy because it is a lot faster (and really order of magnitudes faster).
Some performance optimization can be achived with LINQ-to-SQL using first off precompiled queries. A large part of the cost is compiling the actual query.
http://www.albahari.com/nutshell/speedinguplinqtosql.aspx
http://msdn.microsoft.com/en-us/library/bb399335.aspx
Also you can disable object tracking which may give you milliseconds of improvement. This is done on the datacontext right after you instantiate it.
I also encountered this problem before. The solution I used is Entity Framework. There is a tutorial here. One traditional way is to use LINQ-To-Entity, which has similar syntax and seamless integration of C# objects. This way gave me 10x acceleration in my impression. But a more efficient (in magnitude) way is to write SQL statement by yourself, and then use ExecuteStoreQuery function to fetch the results. It requires you to write SQL rather than LINQ statements, but the returned results can still be read by C# easily.
Certainly there is some type of context switching, marshaling, serializing, etc that takes place when you choose to write a stored procedure in NET vs T/SQL.
Are there any hard facts about this overhead as it relates to making a decision about using .NET vs T/SQL for stored procedures?
What factors do you use in order to make the decision?
For me, developing in C# is 1000% faster than developing in T/SQL due to my learning curve, but when does this gain not offset the performance hit (if there even is one)?
I'd say it depends.
Some things you will find using CLR procedres are better
Using native .NET objects -- file system, network, etc
Using features not offered by TQL or not as good as .NET e.g regular expressions
For yet others you will find TSQL procedures are better, either in terms of ease of use or raw execution speed
Using set based logic (where abc in def or abc not in ghi)
CRUD operations
The overhead is irrelevant in relation to switching, marshaling, etc, unless...your data is not already in the database.
That said, I tend to do almost no stored procedures do as much as possible with T-SQL -- wrapped in an ORM.
Really, that is the answer for there. Look into Entity Framework, NHibernate, Linq To SQL, etc. Get out of writing stored procs (I can hear the down votes now), and do it with C#.
EDIT: Added more info
Stored procs are hard to test (inherently data bound), they offer not speed benefits over dynamic sql, and really are not any more secure. That said, for things like sorting and filtering, a relational database is more efficient than C# will be.
But, if you have to use stored procs (and there are times), use TSQL as much as possible. If you have a substancial amount of logic that needs to be performed, that is not set based, then break out C#.
The one time I did this was to add some extra date processing to my database. The company I was at used a 5-4-4 week-to-month fiscal calendar. That was almost impossible to do in SQL. So I used C# for that one.
It's sort of a religious question, but there can be substantial differences depending on what you're doing, your schema, and how many records you're doing it with. Testing is really the best way to find out for your circumstances.
In general, stored prcoedures will scale better; but that may not be true in your case, or that may not be an important consideration for you.
My understanding of Linq to Sql is it will take my Linq statement and convert it into an equivalent SQL statement.
So
var products = from p in db.Products
where p.Category.CategoryName == "Beverages"
select p
Just turns into
Select * from Products where CategoryName = 'Beverages'
If that's the case, I don't see how stored procedures are useful anymore.
Sprocs are another tool in the box. You might use your fancy automatically-adjusting wrench for 90% of your tasks, but you can't use that shiny thing on stripped nuts. For that a good ol' monkey wrench is your best friend. Unless you break the bolt, in which case you're stuck with assembly.
if that's all you ever did in sql, you didn't need sprocs before!
Security.
I've seen several "security best practice" guidelines which recommend you do all your data access via SP's, and you only grant privileges to execute those SP's.
If a client simply cannot do select or delete on any database tables, the risk may be lower should that client be hacked.
I've never personally worked on a project which worked this way, it always seemed like a giant pain in the backside.
Ah, the subject of many a debate.
Many would argue these days that technologies such as LINQ-to-SQL generate such good SQL these days that the performance advantages are marginal. Personally, I prefer SQL experts tuning SQL performance, not general coders, so I tend to disagree.
However, my main preference for stored procedures has less to do with performance and more to do with security and configuration management.
Much of my architectural work is on service-oriented solutions and by treating the database as a service, it is significantly aided by the use of stored procedures.
Principally, limiting access to the database through stored procedures creates a well-defined interface, limiting the attack surface area and increasing testability. Allowing applications direct access to the underlying data greatly increases the attack surface area, reducing security, and makes impact analysis extremely difficult.
Stored Procedures and Linq to Sql solve different problems.
Linq to Sql is particular to Microsoft SQL Server.
I tend to prefer using stored procedures for several reasons:
it makes the security configuration easier (as mentioned by other posters).
It provides a clearly defined interface for DB access (although responsibility for this could be shifted into other areas, such as a DAL written in C#
I find that the Query Optimizer, in Oracle at least, is able to make more intelligent decisions the more information you give it. This really requires testing with both methods though for your specific scenarios though.
Depending on the developers available, you may have some very good SQL coders who will be better at producing efficient queries if they use sprocs.
The downside is that it can be a pain to keep the code that invokes the sprocs in sync with the database if things are evolving rapidly. The points about producing efficient queries could count as premature optimization. At the end of the day, there is no substitute for benchmarking performance under realistic conditions.
I can think of several good reasons for stored procedures:
When working with bigger tables, it can be hard to generate an efficient query using LINQ to SQL.
A DBA can analyze and troubleshout stored procedures. But think of what happens when two complicated LINQ operations from different front-ends clash.
Stored procedures can enforce data integrity. Deny write access on tables, and allow changes only through stored procedure.
Updating stored procedures is as easy as running ALTER PROCEDURE on a server. If a deployment takes months, and a script minutes, you'll be more flexible with stored procedures.
For a small application that's maintained by one person, stored procedures are probably overkill.
There are significant associated performance improvements on the SQL Server side of things if you use stored procedures in appropriate circumstances.
Stored procedure support for LINQ to SQL was included partly for compatibility with existing systems. This allows developers to migrate from a sproc-based system to a fully LINQ-based system over time, sproc by sproc, rather than forcing developers to make a rush to convert an entire system all at once.
Personally, I don't care for LINQ. I like a separation of the data manipulation stuff and the code stuff. Additionally, the anonymous types that are generated from a LINQ statement cannot be passed-off to other layers of an n-tier application, so either the type needs to be concretely defined, or the LINQ call needs to be made in the UI. Gack!
Additionally, there are the security concerns (whatever user the LINQ code is calling into MS SQL Server under needs to have unfettered access to the data, so if that username/password are compromised, so is the data).
And lastly, LINQ to SQL only works for MS SQL Server (as it comes from MS).
Sprocs have their uses, just like using LINQ does. IMO if an operation is performed multiple times in multiple places then it's a good candidate for "refactoring" into a Stored Proc, as opposed to a LINQ statement that is repeated in different places.
Also, and this is probably blasphemy to a lot of people here, sometimes you should put some logic into the database and then a sproc comes in handy. It's a rare occurrence but sometimes the nature of business rules demands it.
Stored Procedures are useful in many cases, but in General if you are using an ORM you should let the ORM generate the SQL for you. Why should we have to maintain at a minimum of four stored procedures (insert update delete and a single select) for each table.
With that said as people pointed out there are security benefits to using stored procedures. You won't have to grant users read/write to the tables, which is a good protection against SQL Injection.
Stored Procedures are also useful when the logic used to retrieve data is fairly complex. You typicaly see this more in Reporting Scenario's and in which case your probally not using Linq2Sql or some other ORM.
In my opinion if your not generating your SQL but essentially hardcoding it within an app tier, then that should be refactored into stored procedures, and yes there are always exceptions to any rules but in general.
One use of a stored procedure in Linq2Sql might be if you have multiple servers, and are linking to them, you could use a stored procedure to expose data from that other server and manipulate it. This would hide the multiple servers from your application.
Some things can't be done without stored procedures. For instance, at my previous job, there was a stored procedure that return the current value from a row, and incremented it in the same atomic operation such that no two processes every got the same value. I don't remember why this was done instead of using auto-increment, but there was a reason for it.
Reason : Large amounts of data to move from one table to another.
Let's say that once in a while you have to archive items from one table to another or do similar things. With LINQ that would mean to retrieve let's say one million rows from table A into the DBMS client and then insert them into table B.
With a stored procedure things work nice, in sets.
Lots of people have been getting by just fine without them for some time now. If you can do your work securely and efficiently without them, don't feel guilty about going with pure L2S. We're glad to be rid of them # my shop.
You certainly don't "need" stored procedures. But they can come in handy if your domain model requires a complex aggregate Entity and you don't have the luxury/flexibility to modify your database tables to fit your domain model. In this case using Linq-to-SQL or another ORM might result in a very poorly performing set of database calls to construct your Entity. A stored proc can come to the rescue here.
Of course, I would advocate using a methodology or process like TDD/BDD that provides you the flexibility to modify your database tables as needed without much pain. That's always the easier, more maintainable path in my opinion.
Simple example:
select * from Products where GetCategoryType(CategoryName)=1
GetCategoryType can run really fast, because it runs on the DB server.
There's no Linq to SQL substitute for that as far as I know.
I'm coming rather late to this thread. But depending on who you talk to, Linq to SQL is either dead, very dead, or at best a zombie.
In addition, no single tool suits every situation - you need to choose the right tool for the specific job in hand:
Stored procs enable you to enforce complex business rules across multiple client applications.
Stored procs can give you a great security layer.
Stored procs can give you a great abstraction layer.
Stored procs can give you better caching in some circumstances.
I made a fairly large social network type website and used nothing but inline SQL Statements to access the database (I was new to the language so back off!)
Are there any performance issues when doing it this way as opposed to using a massive XSD DataSet file to handle all the queries? Or is this just bad design?
Thanks!
When you reach real DB performance issues it won't really matter (performance wise) whether you're using stored procedures or direct SQL statements.
Your best bet in that situation is to avoid DB in the first place. In other words, it would be better to plan and architect a good caching mechanism because that will make all the difference when it really comes to serious traffic.
Stored procedures or inline code... again, performance wise (i'm not talking about maintainability, security, ...) simple doesn't matter that much anymore.
I think the maintenance issue/cost will have much more impact, will be much greater then the performance impact (if there's any performance impact at all).
If it is SQL Server changing your Inline SQL Statements to be parametrised calls to sp_ExecuteSQL should yield a very significant performance improvement - and would probably be easier to refactor than moving to, say, Stored Procedures instead of inline code.
IME ultimately, Stored procedures that return multiple recordsets (i.e. do several pieces of work / logic, rather than just replace single in-line queries) would yield more performance improvements.
Strictly speaking the SQL performance would be better if you use inline sql statements rather than an XSD Dataset. This is assuming that at a minimum you use parameterized queries (although SQL Server 2005 even optimizes for non-parameterized queries).
The statement that inline sql cannot be optimized by the database engine isn't true. Stored procedures are optimized identically to inline sql with SQL Server.
But whether it makes sense from a design perspective is another story entirely. And whether you are over-optimizing too early is another question.
Stay away from generated typed datasets. The performance isn't that good. If you need the type of functionality, look at LINQ; otherwise just grab the Enterprise Library and go direct.
When having large amount of data a DB is better in ways of: maintenance and performance. Having stored procedures for example makes it possible to delegate the work and query-optimizations to a professional DBA, no recompiles are needed. When having XSD/XML data files, you have to regenerate your code for each change.
Also look at concurrency: more users, more web-request, more concurrency... you can end up in locks in the data file. You could implement advanced caching mechanisms to gain more performance but that's also extra maintenance and complexity.