I’m storing items that are tied to a time of day associated with an “impact”.

For example, an item might have one or more tuples of

(8:30 AM, "High"),
(8:30 AM, "Medium"),
(9:30 AM, "High"),
(10:00 AM, "Medium")

The quick-and-dirty solution was to store this as a string, like:

0830-H_0830-M_0930-H_1000-M

… but that causes some problems when trying to to determine if an item contains/excludes one more given time tuples (and probably doesn’t perform well compared to the alternatives).

What’s the proper way to go about storing this efficiently for querying in ClickHouse?

There aren’t too many variations of this data – perhaps a couple dozen or so (if even that much).