Is there a version control system for database structure changes?

Question

I often run into the following problem.

I work on some changes to a project that require new tables or columns in the database. I make the database modifications and

Answer 1

Schema Compare for Oracle is a tool specifically designed to migrate changes from our Oracle database to another. Please visit the URL below for the download link, where you will be able to use the software for a fully functional trial.

http://www.red-gate.com/Products/schema_compare_for_oracle/index.htm

Answer 2

Have your initial create table statements in version controller, then add alter table statements, but never edit files, just more alter files ideally named sequentially, or even as a "change set", so you can find all the changes for a particular deployment.

The hardiest part that I can see, is tracking dependencies, eg, for a particular deployment table B might need to be updated before table A.

Answer 3

I'd recommend one of two approaches. First, invest in PowerDesigner from Sybase. Enterprise Edition. It allows you to design Physical datamodels, and a whole lot more. But it comes with a repository that allows you to check in your models. Each new check in can be a new version, it can compare any version to any other version and even to what is in your database at that time. It will then present a list of every difference and ask which should be migrated… and then it builds the script to do it. It’s not cheap but it’s a bargain at twice the price and it’s ROI is about 6 months.

The other idea is to turn on DDL auditing (works in Oracle). This will create a table with every change you make. If you query the changes from the timestamp you last moved your database changes to prod to right now, you’ll have an ordered list of everything you’ve done. A few where clauses to eliminate zero-sum changes like create table foo; followed by drop table foo; and you can EASILY build a mod script. Why keep the changes in a wiki, that’s double the work. Let the database track them for you.

Answer 4

ER Studio allows you to reverse your database schema into the tool and you can then compare it to live databases.

Example: Reverse your development schema into ER Studio -- compare it to production and it will list all of the differences. It can script the changes or just push them through automatically.

Once you have a schema in ER Studio, you can either save the creation script or save it as a proprietary binary and save it in version control. If you ever want to go back to a past version of the scheme, just check it out and push it to your db platform.

Answer 5

In the absence of a VCS for table changes I've been logging them in a wiki. At least then I can see when and why it was changed. It's far from perfect as not everyone is doing it and we have multiple product versions in use, but better than nothing.

Answer 6

MyBatis (formerly iBatis) has a schema migration, tool for use on the command line. It is written in java though can be used with any project.

To achieve a good database change management practice, we need to identify a few key goals. Thus, the MyBatis Schema Migration System (or MyBatis Migrations for short) seeks to:

• Work with any database, new or existing
• Leverage the source control system (e.g. Subversion)
• Enable concurrent developers or teams to work independently
• Allow conflicts very visible and easily manageable
• Allow for forward and backward migration (evolve, devolve respectively)
• Make the current status of the database easily accessible and comprehensible
• Enable migrations despite access privileges or bureaucracy
• Work with any methodology
• Encourages good, consistent practices