Attach and Detach database in SQL Server | copy databases in sql server | sql attach database

[@webcoderltd]

H, finally you cast some light on the Attach - Detach or Detach - Attach (AD/DA) method. However, at the beginning you're stating that you use DA you loose the database from the source. I understand one doesn't have to loose it and run the same database on multiple separate SQL servers (presumably even on the same server when db name is amended during attach so it doesn't clash) and there's no difference to Backup and Restore (BaR) apart from file sizes that get compressed? I also can't find any solid information on user accounts and permissions to the copieed or moved database that exist in source - logically they would be lost and manually recreated in destination?
We currently have a 1.2TB database in SQL 2016 server that needs to be migrated over to SQL 2019 server. We would like to do a test migration so I was thinking that DA method would be the quickest as we don't have anymore space for storing SQL backup files and both servers are on the same 1Gbps or even 10Gbps LAN hence copying 1.2TB should be really quick. I would deach server A SQL 2016 db, copy files across to to server B SQL 2019 then reatttach source and attach destination to have a running exact close at this point in time in order to run some tests.
Cheers,
David

[@marthamesfin3509]

I was trying to detach my DB following your video. However, it fails to detach instead /single user/appears on the side of the DB what did I do wrong?

[@babeelpjabbar7162]

Thankyou so much🤩

[@Training2SQLMSBI]

You’re welcome 😊

[@SisoSiso-x3e]

thanks Sir

[@Training2SQLMSBI]

thanks for your valuable feedback.

[@tavamaniarumugam5084]

Thank you.

[@Training2SQLMSBI]

You're welcome!