The zoom window tracks the mouse pointer and provides a blow up of the piece of the model your cursor is currently over.  As you gain experience modeling and work on your own, you'll utilize this feature every once in a while.  For some of your modeling, it can get distracting  so I normally turn it off.  I use a standard coloring scheme to designate a particular type of entity such as parent, child, denormalized table, view, etc.  Where the zoom window comes in very handy is when you have a model put together, color coded, and zoomed out so that you can see the entire model.  You usually do this when wanting to rearrange the placement of entities so that you get a "nice pretty picture" of your database.  The zoom window will track and help you find the objects you are looking for.

The explorer is another of those unique features which is extremely useful.  It is shown below.

In this image, you can see the three tabs I described above.  The other thing you'll notice is the Logical and Physical entries.  ER/Studio gives you simple and seamless access to both the logical and physical data model.  PowerDesigner stores each of these as two separate files.  ERWin makes you go through some contortions on the menu to get to the logical model.  With ER/Studio, you simply click the Logical entry and you are now looking at the Logical model.  You'll also notice that each of the entities opens up as well displaying the attributes/columns that currently make up each entity.  From the Explorer, you can edit, delete, or rename an entity or attribute/column.  If you are deleting columns, I would encourage you to use the explorer.  ER/Studio has an irritating feature when working in the editors of prompting you to save every time you make a change.  If you want to delete four columns, you will see this dialog 4 times.  This "feature" is being removed in the next release.  For now, you can save yourself some time by using the explorer.  One other thing the explorer allows is multi-selecting.   This means you can delete a group of columns in a single operation.  While you can change an entity or attribute/column name from the explorer, there is a much easier way.  Simply zoom the display until you can see the entity you want to modify.   Then just shift+click the entity or attribute/column and it will automagically be placed in an editing mode similar to what you see when renaming a file using Windows Explorer.

One big note: Do not turn on autosave and be careful inside of your model.   Autosave does not function the same as in all other products you are used to.   The autosave in all other products will periodically write your "document" to a temporary file.  When you save or close the "document" it is deleted.  When the software starts up it checks to see if any of these files are around indicating a system crash that needs to be recovered from.   The autosave in ER/Studio overwrites the actual file.  It is exactly the same as if you hit the save button on a regular schedule.  I recommend never turning this on.  The other reason to be careful is that there is no undo feature.  Once something is done, that is it.  The only way of going back is to close the model without saving and open it back up.

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