Every object in SSAS database, such as a Cube, a Measure Group, a Measure and a Dimension, has an ID which is generated automatically when the object is created. The ID, once generated, cannot be changed from the Properties window of the object; it is read-only. When an object is created, by default, object name and it’s ID are same, however, over a period, objects get renamed leaving the ID with old value. In majority of situations, this does not create a problem but there are a few cases when this can be problematic. Now some people might say I have an OCD (Obsessive Compulsive Disorder) but I like my object names and IDs to be consistent.For most of the objects, the ID can be changed by opening the object code (right click–> View Code) and changing the value in <ID> tag. A word of warning though, be extremely careful when changing the IDs. It can create quite an issue in your project. For example if you change ID of dimension, you would have to make same change in cube XML else you would loose the relationship.
Anyway, that’s all find and dandy. But how would you change the database id? If you rename the database, the ID does not change and there is no View Code for project. As it turns out, it is in *.database file of the project. In Solution Explorer, click on Show All Files. You would see a your_project_name.database file. Right click on it and then View Code. You will find <ID> tag which contains the ID of the database.