MySQL Bugs: #101739: Slow performance upgrading to MySql.Data.EntityFrameworkCore 8.0.22

Bug #101739	Slow performance upgrading to MySql.Data.EntityFrameworkCore 8.0.22
Submitted:	24 Nov 2020 23:26	Modified:	9 Dec 2020 16:15
Reporter:	Matt Stubblefield	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	Connector / NET	Severity:	S3 (Non-critical)
Version:	8.0.22	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
Upon upgrading from MySql.Data.EntityFrameworkCore 8.0.21 to 8.0.22 I noticed some serious performance implications. My code was performing at half speed. Especially on result sets with a lot of rows (not sure if this matters).

How to repeat:
- Create a "shared" .net core project and reference the Entity Framework Core 3.1.10.
- In the shared project, create a query using entity framework- I called mine several times in a loop to get a benchmark
- Wrap it with a stopwatch for timing and print out the resulting time elapsed
- Create a parent project and reference MySql.Data.EntityFrameworkCore 8.0.21
- Create another parent project and reference MySql.Data.EntityFrameworkCore 8.0.22
- All projects should be calling to the same shared query and have the same connection string.

Upon viewing the results, the 8.0.22 code should be much slower (in my case 8.0.21 was twice as fast as 8.0.22).

This may be a duplicate of bug #101714. Are you able to profile your application and see if the slowdown is caused by calling the Regex constructor?

This is 100% a duplicate! Please close.

Thank you for the feedback. Duplicate of https://bugs.mysql.com/bug.php?id=101714.