How can you efficiently store a list of all blog tags?

Question

Blogs

The blog script loads the catalog of publications stored in the database page by page.
Publication tags are stored in the database in a non-normalized column, that is, as a comma-separated list of tags. (as far as I understand, this task is not subject to normalization) # A,B,C
Along with the directory, the script should load the tag cloud of all blog posts (however, the cloud is specific: if the directory already shows entries for a specific tag A, then the cloud should consist of all tags of posts that have the tag A )
How do you think, how can you effectively set up the display of a tag cloud? Is there any way to normalize the database? Maybe memoize? But how then to store these values? Thank you.

Answer 1

Why is it not normalized? Separate tags table and posts and tags relation table (many-to-many relationship).