Nicolas Dumazet wrote:
I am thinking of a table containing for each category page title the cat_id it refers to. When updating a page, a query joining that table and the category table could retrieve A) the cat_id needed to update category_links B) possibly the cat_title to display the "proper" links at the bottom of the article.
To clarify a bit my point, I'm saying that when Category:A redirects to Category:B, articles belonging to A and B should point to the same cat_id
Not sure if i'm understanding you, but are taking into account that after merging categories A and B (by way of making a redirect from A to B) someone may revert/split it by making A a different category? I think that could be the reasoning for cl_to_id. And that use case is tricky enough to break many easy solutions :)