Database deployments - dotnetsheff 2 March 2021 https://www.meetup.com/dotnetsheff/events/273184959/

1. Database deployments
Giulio Vian — 3 March 2021

2. In a Start-up far far away
DBA
Senior
Dev
Scrum
Master
Junior
Dev

3. Free!
too good to be true
• 0 $/£/€ = gratis!
• open source
• any DB!
• 1,400 stars
• and works!

4. Months
pass
It’s Friday:
Let’s deploy the
latest version!

5. Unpleasant situation

6. Migration-based
Source: https://www.red-gate.com/hub/product-learning/sql-source-control/moving-from-application-automation-to-true-devops-by-including-the-database

7. Baseline (aka v0.0.0)

8. Independent migration scripts
Conflict?

9. let’s use dacpac

10. Truth revealed

11. State-based
Source: https://www.red-gate.com/hub/product-learning/sql-source-control/moving-from-application-automation-to-true-devops-by-including-the-database

12. Baseline (aka v0.0.0)

13. Baseline (aka v0.0.1)

14. Diff script from schema-based tool
uh oh

15. Help me

16. Migration based
v1  v2
Hides conflicts
Order matters
State based
v1  v2
Miss object renames
Rollback drifts
Schema evolution

17. Migration based
v1  v2
State based
v1  v2
What to use

18. Your path you must decide

19. Are the two mutually exclusive?
No
Dev can use a Schema diff tool like SSDT to draft
migration scripts
Migration script can be augmented stating the baseline
version
State-based tools have pre- and post-deploy phases for
data migration
We can add dependency check between migration
scripts
To warn about scripts interaction and dependency

20. Hardware spec:
1 KB RAM
(16KB after upgrade)
4 KB ROM
(8KB after upgrade)
First computer Past Companies Communities
Giulio Vian Senior DevOps Engineer
@giulio_vian
giuliovdev@hotmail.com

21. References
Tools
SQL Server Data Tools (SSDT)
RedGate SQL Compare
devart
Flyway
dbup
dbdeploy.net
Articles
https://en.wikipedia.org/wiki/Sc
hema_migration
https://martinfowler.com/article
s/evodb.html
https://michaeljswart.com/2018
/01/100-online-deployments
http://blog.dixo.net/2015/02/bl
ue-turquoise-green-deployment
Books
Refactoring Databases:
Evolutionary Database Design
http://www.agiledata.org/

22. Thank you!
Giulio Vian
@giulio_vian
giuliovdev@hotmail.com

23. Deployment Process

24. Database Refactoring Cycle
Initial state Final state
Implement the refactoring
Test on non-production
Refactoring completed
deploy new schema,
migrate data
deploy new application version

25. Database Refactoring Cycle
Initial state Final state
Implement the refactoring
Test on non-production
Refactoring completed
deploy new schema,
migrate data
deploy new application version

26. Database Refactoring Cycle
Initial state Final state
Transitional state
Implement the refactoring
Test on non-production
Refactoring completed
All systems use the new schema
Coexistence of
old and new schema
Expand:
deploy new schema,
migrate data,
add scaffolding code
Contract:
Drop old schema objects
and scaffolding code

27. Recapping

28. applications
DATa

29. La morale
Tools are
limited
Know your
stuff is the
only way
Discipline

30. Migration troubles
with DbUp
also FlyWay, Liquibase, etc.

31. State troubles
with dacpac