Home
Help
Register
Log in

Search

 
   Active Threads  

You are here: Home > LLBLGen Pro > Architecture> Mis-understanding about DynamicQueryEngine.UseNoLockHintOnSelects
 

Pages: 1
Architecture
Mis-understanding about DynamicQueryEngine.UseNoLockHintOnSelects
Page:1/1 

  Print all messages in this thread  
Poster Message
sasaki
User



Location:
Kyoto
Joined on:
23-May-2019 10:03:45
Posted:
3 posts
# Posted on: 16-Jan-2020 20:00:39.  
One of my developer trying to use DynamicQueryEngine.UseNoLockHintOnSelects = true to fixing the query performance. But when I read the manual in this link,
https://www.llblgen.com/documentation/5.3/ReferenceManuals/LLBLGenProRTF/html/9363447C.htm , it says that UseNoLockHintOnSelects may cause more blocking. How can blocking occurs because as I understand it will work same as READUNCOMIT Isolation level?

Quote:

WITH NOLOCK is not recommended though in high volume databases with a lot of rows, it can be a lot of blocking can occur because SqlServer forces readers to block writers and vice versa.


Thank you!
  Top
Otis
LLBLGen Pro Team



Location:
The Hague, The Netherlands
Joined on:
17-Aug-2003 18:00:36
Posted:
37797 posts
# Posted on: 17-Jan-2020 09:50:50.  
That's indeed an error in the docs. We'll correct it for the supported versions. Thanks for the heads up!

What performance issues were you running into btw? The particular feature is a rather old one and is a setting that's applied to all queries. We introduced in v5.1 a per-query target/query hints in v5.5, which might be better suited in your situation.


Frans Bouma
LLBLGen Pro / ORM Profiler Lead Developer | Blog | Twitter
 
Top
Otis
LLBLGen Pro Team



Location:
The Hague, The Netherlands
Joined on:
17-Aug-2003 18:00:36
Posted:
37797 posts
# Posted on: 17-Jan-2020 10:36:01.  
While looking into why that remark was there in the first place, I ran into: https://bertwagner.com/2017/10/10/how-nolock-will-block-your-queries/

So nolock isn't without locks. It therefore depends on what the query is doing, and when. We'll still remove the wrong remark tho Regular Smiley
Frans Bouma
LLBLGen Pro / ORM Profiler Lead Developer | Blog | Twitter
 
Top
Pages: 1  


Powered by HnD ©2002-2007 Solutions Design
HnD uses LLBLGen Pro

Version: 2.1.12172008 Final.