The book is very good, it really addresses the needs of absolute beginners. I would like to take the opportunity to ask ask experienced programmers a question. It is not related to the source code for the book ( there is no appropriate place on this board to post it) so in that sense the question is out of place.
Suppose that the application Bookstore discussed in chapter 5 is completed, and it logs every piece of printed material sold and stores the record. After some time we have thousands of records stored. Each maintains the data specified in UML diagram. Additionally, we did not implement Find function in the program or any analytic capabilities in the program. And our Bookstore program is not a database, it just creates a lot of documents with different types of data, it's created with Swift.
Here is my question: is it possible to use some externally developed tool to conduct business analysis of the stored information (sales records)? Taken from slightly different angle: if you have a stack of documents ( mixed data types all known to you) can you attempt a query after indexing the documents using something like ElasticSearch?
Again, sorry for off the theme question, but i didn't know where else to post it.