We start the development of an ebook store based on virtuemart (http://www.myebooks.gr
) and very quickly it grew to a large bookstore with more than 8 Millions products http://www.cosmotebooks.gr
In order to achieve this product capacity we did a lot of code modification and database optimisation, basically we added caching mechanisms and we integrated SOLR for searching and filtering. We extend almost every functionality of virtuemart in order to accommodate business requirements and we developed an number of modules and plugins.
Because the base product was book we added new tables and fields, like the authors and the kind. The kind is high level taxonomy and each kind has its own category tree, authors, manufactures, discounts and others. It help us manage the large quantity of products and divide the site to mini-sites one per kind.