How does Clickhouse sort data if primary / sorting key is number

Question

I'm wondering how will Clickhouse sort data internally if I use number as primary key. In documentation they say:

The inserted rows are stored on disk in lexicographical order (ascending) by the primary key columns

which would (maybe) imply that numbers are looked as strings and for example 10000 is lower / before 2, but when looking at their examples in the same documentation link, when they sort by UserID field which is UInt32, it looks like data is actually sorted by numbers (and not their lexicographical representation) so row with UserID of value 240923 is before row with UserID of value 10487847

My guess and expectation is that numbers (and other types like dates) are sorted as we would expect those types to be sorted so that order by clause later on can use primary / sorting key but I just wanted to double check.

Thanks!

Answer 1

Your guess is correct: numbers are sorted by size, strings are sorted lexicographically...always ascending.