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SQL Server Migration Overview

It’s Not Just Backup / Restore At some point every company faces it: the SQL Server that’s been quietly running for years is due for retirement. Maybe the hardware...

2025-10-22

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Blog Post

SQL Server Alerts

Don’t Let Trouble Sneak Up on You   Most SQL Servers run quietly. Until they don’t. By the time someone notices an application outage or a failed backup, you’re...

2025-11-03 (first published: )

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Blog Post

SQL Server is Slow, part 3 of 4

In parts 1 and 2 of this series, we’ve gathered info and done the triage just like anyone in almost any industry does At this point you’ve: Defined what...

2025-10-27 (first published: )

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Blog Post

SQL Server Is Slow (part 1 of 4)

How should you respond when you get the dreaded Email/Slack/Text/DriveBy from someone yelling at you that SQL Server is slow?   Stop. Don’t Open SSMS Yet. You’ve heard it...

2025-10-08 (first published: )

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Blog Post

SQL Server Availability Groups

Flexibility and Scale at the Database Level When SQL Server 2012 introduced Availability Groups (AGs), they changed the HA/DR game. Unlike Failover Cluster Instances (FCIs), which protect the whole...

2025-09-10

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Blogs

Why Optimize CPU for RDS SQL Server is a game changer

By

One feature that I have been waiting for years! The new announcement around optimize...

Performance tuning KubeVirt for SQL Server

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Following on from my last post about Getting Started With KubeVirt & SQL Server,...

T-SQL Tuesday #193 – A Note to Your Past, and a Warning from Your Future

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I haven’t posted in a while (well, not here at least since I’ve been...

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Forums

Refactoring SQL Code

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Refactoring SQL Code, which is...

The Read Committed Snapshot Isolation behaviour

By Alessandro Mortola

Comments posted to this topic are about the item The Read Committed Snapshot Isolation...

Working with JSON/JSONB Data in PostgreSQL using Python

By sabyda

Comments posted to this topic are about the item Working with JSON/JSONB Data in...

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Question of the Day

The Read Committed Snapshot Isolation behaviour

I am currently working with Sql Server 2022 and AdventureWorks database. First of all, let's set the "Read Committed Snapshot" to ON:

use master;
go

alter database AdventureWorks set read_committed_snapshot on with no_wait;
go
Then, from Session 1, I execute the following code:
--Session 1
use AdventureWorks;
go

create table ##t1 (id int, f1 varchar(10));
go

insert into ##t1 values (1, 'A');
From another session, called Session 2, I open a transaction and execute the following update:
--Session 2
use AdventureWorks;
go

begin tran;
update ##t1 
set f1 = 'B'
where id = 1;
Now, going back to Session 1, what happens if I execute this statement?
--Session 1
select f1
from ##t1
where id = 1;
 

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