How to make an index for a custom sort?

Question

PostgreSQL

In general, there is a table items(id,category_id,c1,c2,c3,c4), where id is the primary key, category_id is the category of the item, and there are some parameters (c1,c2,c3,c4), and these parameters have some restrictions: c1 - can take values ​​1 or 2, c2 - from 1 to 100, c3 - from 1 to 100, c4 is a UNIX timestamp. You need to create an index for the following query: SELECT * FROM items WHERE category_id = $1 ORDER BY $2 DESC, $3 DESC, $4 DESC, $5 DESC. Where everything in ORDER BY is parameters c1 to c4, which are defined by the user. By the way, a separate case may be when some fields may be missing, that is, just be ORDER BY $2 DESC, $3 DESC. I don’t know how to make an index for this, this is actually the question. It is possible to implement this outside of SQL.

Answer 1

Hang a common index on all 4 fields