How should you build your database from source control?

Question

There has been some discussion on the SO community wiki about whether database objects should be version controlled. However, I haven\'t seen much discussion about t

Answer 1

Here are some some answers to your questions:

1. Should both test and production environments be built from source control? YES
   • Should both be built using automation - or should production by built by copying objects from a stable, finalized test environment?
   • Automation for both. Do NOT copy data between the environments
   • How do you deal with potential differences between test and production environments in deployment scripts?
   • Use templates, so that actually you would produce different set of scripts for each environment (ex. references to external systems, linked databases, etc)
   • How do you test that the deployment scripts will work as effectively against production as they do in test?
   • You test them on pre-production environment: test deployment on exact copy of production environment (database and potentially other systems)
2. What types of objects should be version controlled?
   • Just code (procedures, packages, triggers, java, etc)?
   • Indexes?
   • Constraints?
   • Table Definitions?
   • Table Change Scripts? (eg. ALTER scripts)
   • Everything?
   • Everything, and:
     • Do not forget static data (lookup lists etc), so you do not need to copy ANY data between environments
     • Keep only current version of the database scripts (version controlled, of course), and
     • Store ALTER scripts: 1 BIG script (or directory of scripts named liked 001_AlterXXX.sql, so that running them in natural sort order will upgrade from version A to B)
3. Which types of objects shouldn't be version controlled?
   • Sequences?
   • Grants?
   • User Accounts?
   • see 2. If your users/roles (or technical user names) are different between environments, you can still script them using templates (see 1.)
4. How should database objects be organized in your SCM repository?
   • How do you deal with one-time things like conversion scripts or ALTER scripts?
   • see 2.
   • How do you deal with retiring objects from the database?
   • deleted from DB, removed from source control trunk/tip
   • Who should be responsible for promoting objects from development to test level?
   • dev/test/release schedule
   • How do you coordinate changes from multiple developers?
   • try NOT to create a separate database for each developer. you use source-control, right? in this case developers change the database and check-in the scripts. to be completely safe, re-create the database from the scripts during nightly build
   • How do you deal with branching for database objects used by multiple systems?
   • tough one: try to avoid at all costs.
5. What exceptions, if any, can be reasonable made to this process?
   • Security issues?
   • do not store passwords for test/prod. you may allow it for dev, especially if you have automated daily/nightly DB rebuilds
   • Data with de-identification concerns?
   • Scripts that can't be fully automated?
   • document and store with the release info/ALTER script
6. How can you make the process resilient and enforceable?
   • To developer error?
   • tested with daily build from scratch, and compare the results to the incremental upgrade (from version A to B using ALTER). compare both resulting schema and static data
   • To unexpected environmental issues?
   • use version control and backups
   • compare the PROD database schema to what you think it is, especially before deployment. SuperDuperCool DBA may have fixed a bug that was never in your ticket system :)
   • For disaster recovery?
7. How do you convince decision makers that the benefits of DB-SCM truly justify the cost?
   • Anecdotal evidence?
   • Industry research?
   • Industry best-practice recommendations?
   • Appeals to recognized authorities?
   • Cost/Benefit analysis?
   • if developers and DBAs agree, you do not need to convince anyone, I think (Unless you need money to buy a software like a dbGhost for MSSQL)
8. Who should "own" database objects in this model?
   • Developers?
   • DBAs?
   • Data Analysts?
   • More than one?
   • Usually DBAs approve the model (before check-in or after as part of code review). They definitely own performance related objects. But in general the team own it [and employer, of course :)]