Popular Bookstore and its computer system

Remember, last week, I wrote the story about Amcorp Mall and my search for a book in Popular Bookstore.

After not finding the book in the bookshelves, I went to one of the sales assistants for, well, assistance.

I could recall the name of the author and the title of his second book, called The Pirate Inside, which I currently read. However, I wanted to have his first book and couldn't recall that title at that time (Its called Eating the Big Fish).

Now, Popular's computer system didn't throw up any title by the author, so I asked her if she could find the first book, when I would give her the title of the second book. It is not possible, she responded.

Apparently, their database makes it possible to find books by an author, and by specific titles. However, if the different books are placed at different locations in the store, it is not possible for the store assistant to find the book. My question is, why not? I mean, a cross reference should be possible, right? I am not a total expert or would not even call me knowledgeable about computer database (besides MS Access), but what I do know is that they lost a sale! Is this just this Popular bookstore, or is this happening in different locations as well?