I understand you have a lot of pages and page types. What I'm stating is you might look into a supported version or change in order to get what you want accomplished faster and not cause problems later on. If you're creating views in the database directly, there's a good chance your're going to end up creating a breaking change to your instance which will not be supported. I'd suggest contacting Kentico directly for their recommendation.
Yes, I understand you're almost half way through fixing it but it was documented and with a site that has that much content, I wouldn't have upgraded it do a vanilla major version of any CMS. I would have waited until a few hotfixes were out, ensure you have all issues documented with the upgrade and your instance planned for upgrade and ensure you have a good testing plan in place.
For future reference here are the release notes for Kentico 9. Check out the database section, it has all the changes to the database as well as the views you're referencing. The very first bullet point states "All page related views and the View_COM_SKU views were removed with the exception of View_CMS_Tree_Joined, which is used as the base for querying of page data".
A solution might be to create a custom query in the page type and include the page type class and FK value like below. Then use the ObjectQuery to call it and pass your values to it. I do this will all my queries, even queries to external sources. This way the can be modified within the UI and the database remains untouched.
SELECT ##TOPN## ##COLUMNS##
INNER JOIN Custom_Slider ON DocumentForeignKeyValue = SliderID AND ClassName = 'custom.slider'
ORDER BY ##ORDERBY##
Good luck with the rest of your upgrade!