Thursday, January 24, 2008

what has changed for a rebase?

Some new developers came to ask the question: "I did a rebase. But I could not see any rebase activities. Did the rebase successful? If so, what's changed after the rebase?"

These are valid questions. In fact, they are very good questions. Normally after a rebase, you will notice that there is a new activity with a title like "rebase ...". These activities contain the change set for the rebase operation. However, sometimes, the rebase operation does not generate the "rebase..." activity. That's when people come up with the questions.

A rebase operation changes the foundation baseline of the stream from the previous recommend baseline of the parent stream to the current one. If you do not change any file in the delta of the two baselines, i.e, you do not touch the same files as the recommended baseline, you will not get a rebase activity. However, your view will reflect the new version of the elements. When you check out the files in the future, they will be branched out from the new versions. If you have changed the files in the delta, ClearCase will do the merge for you, and you will see the rebase activity. From the version tree, a merge arrow will be drawn from the recommended version to your version.