Month: November 2021

Performance Improvements in .NET 6

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There have been a large number of Performance Improvements in .NET 6 as evidenced in Stephen Toub’s blog post. Most of the time we don’t care about assembly level performance optimisations because the bottleneck is usually accessing some external resource, such as a database or web service.

If you need to benchmark .NET code take a look at a great tool, BenchmarkDotNet and also take a look at the book referenced there, Pro .NET Benchmarking as getting benchmarking correct can sometimes be quite tricky.

If you’re not yet on .NET 6, and you have code in a large loop that you want to squeeze some performance out of it (and it won’t make the code hard to understand and maintain!) here are a couple of simple tips:

  • Testing if n is even: replace (n % 2 == 0) with ((n & 1) == 0)
  • Dividing by 2: replace n / 2 by n >> 1 (but be aware of the unsigned / signed behaviour of right shift)

LINQPad script to Generate SQL Server Database Restore Script from Ola Hallengren’s Backup Solution

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Unless you perform regular restores of your database backups, you don’t know that you actually have a valid backup. In a career spanning over 30 years, I’ve seen two occasions where a company was performing backups (or so they thought!) and sending tapes offsite, assuming they were good when in fact the tapes were blank!

The majority of SQL Server installations use Ola Hallengren’s maintenance solution (and certainly all the ones I’ve had anything to do with).

If you are doing regular (5 minutes or less) transaction log backups, a restore might involve applying quite a few transaction logs.

I’ve written a short LINQPad script here which will generate the TSQL to perform a database restore either from a point in time or the latest available, based upon the default locations and naming conventions used by Ola’s backups. It’s Differential backup aware, as well as creating the multiple Transaction Log restore statements. It’s also takes into account where backups are split into separate backup files (which is quite common). You specify the server name, the database name, the root folder where the backups are stored, and either a point in time or the latest.

Disclaimer: Use at your own risk AND test thoroughly!

Example output:

USE [master]

RESTORE DATABASE [AdventureWorks] FROM 
   DISK = N'C:\temp\Backup\K7\AdventureWorks\FULL\K7_AdventureWorks_FULL_20211118_151558.bak'
 WITH NORECOVERY, REPLACE

RESTORE DATABASE [AdventureWorks] FROM 
   DISK = N'C:\temp\Backup\K7\AdventureWorks\DIFF\K7_AdventureWorks_DIFF_20211118_152101.bak'
 WITH NORECOVERY

RESTORE DATABASE [AdventureWorks] FROM 
   DISK = N'C:\temp\Backup\K7\AdventureWorks\LOG\K7_AdventureWorks_LOG_20211118_152226.trn'
 WITH NORECOVERY, STOPAT = '2021-11-21 17:07:22'

RESTORE DATABASE [AdventureWorks] WITH RECOVERY