Custom change: can I designate a field as not affecting the checksum?

General Discussion
1

We are using Liquibase 2.0.1.  (Subsequent versions add PRIMARY KEY DDL fragments to almost every DDL line in the Informix support.)


Here are my class signatures, condensed etc. for brevity:


Laird Nelson - Bainbridge Island, Washington, Oracle, Amherst College, Lakeside School | about.me

2

Is there a way to designate a particular attribute of a custom change as not affecting the changeset’s checksum?


Background: I’ve written a column copying change/refactoring element that accomplishes copying and data conversion through a JDBC driver, rather than in SQL (Informix, curse its awful soul, can’t convert a VARCHAR to a TEXT column in SQL).  To make this reasonably performant I’ve added a fetchSize attribute.  I now can’t add this attribute to our existing usages of this custom refactoring element because it alters the checksum of the changeset of which they are a part.


I know that Liquibase features some annotations to help in this general area, but I couldn’t find anything obvious.


Best,

Laird

–
http://about.me/lairdnelson

3

What version of liquibase are you using? 2.x? And by “custom change” do you mean a customChange implementation or a class that actually extends the Change interface as a liquibase extension?

Nathan

4

That’s what I was trying to remember; thank you!

–
http://about.me/lairdnelson

5

Thanks for finding that nessumo. I did create https://liquibase.jira.com/browse/CORE-1330 to separate out whether a field is serializable from whether it is used in checksums.


Nathan

6

I guess you can use AnonymousChange for exemplary use.

7

In 3.0.7 the annotation changed to DatabaseChangeProperty. There is probably too much connection between “all properties” and “serializable properties” and “properties to checksum”. I should clean that up more in 3.1.  


You can set the @DatabaseChangeProperty(isChangeProperty  = false) attribute and that should allow your change to still work but will not try to checksum it.


I created https://liquibase.jira.com/browse/CORE-1634 to track the API changes


Nathan

8

Hmm… I have problem now, during upgrade to 3.0.7. Above annotation is no longer available, but your issue is not yet solved. Any idea? :wink:

9

I know this is a very old issue, but I think I have a similar problem, where a property is marked as being associated to a specific RDBMS which then changes e.g. ‘mysql’ to ‘mariadb’.

For example, for years we had:
<property name="now" value="now()" dbms="mysql"/>
When we migrated to mariadb, this property becomes unset, and we must change the changeset to:
<property name="now" value="now()" dbms="mariadb"/>
However this calculates a change in the checksum and running a migration fails. We can clear the checksums but it would be nice to have a future proof way of saying “this change is not significant to the checksum”.

See also discussion at potential feature - ignore checksum - #3 by un1376926463332r33id

Is this annotation DatabaseChangeProperty available, and how would we use it in an XML file, please?