Dallas DBAs

Blog Post

Virtual Log Files

Today’s post is a guest article from a friend of Dallas DBAs, writer, and fantastic DBA Jules Behrens (B|L) One common performance issue that is not well known that...

2020-12-07 (first published: )

384 reads

Blog Post

Renaming SQL Server Databases

Video walkthrough of renaming or “flipping” databases to minimize down time during a refresh.  Most commonly when moving a copy from prod to dev. My Pluralsight courses for new...

2020-10-12

38 reads

Blog Post

SQL Server Express Size Limit

My Pluralsight course for new SQL Server DBAs   (Needs to upgrade to a bigger bowl) Common scenario: Company is using SQL Server Express to save on licensing costs...

2020-07-02

232 reads

Blog Post

TIL: Dismount-DbaDatabase and Mount-DbaDatabase

We have a double feature for today’s dbatools blog post, as these two commands go hand-in-hand. Todays commands: Dismount-DbaDatabase and Mount-DbaDatabase Detach-DbaDatabase and Attach-DbaDatabase can be used as aliases....

2020-07-01 (first published: )

215 reads

Blog Post

TIL: Get-DbaErrorLog

Ed: SQLDork is a Junior DBA on the team here, learning the DBATools in addition to normal DBA stuff™ Today’s dbatools command is Get-DbaErrorLog, which is very similar to...

2020-05-29

28 reads

Blog Post

TIL: Measure-DbaBackupThroughput

Today’s dbatools command: Measure-DbaBackupThroughput This one’s a smaller command, but that doesn’t mean it’s without use. If you need information on backup speeds (throughput) or early warning of possible...

2020-05-26

21 reads

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

By

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

By

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

Read the latest Blogs

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...

Visit the forum

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;
 

See possible answers