PromQL: Dot in regexp should also match newlines (which is less surprising to most users and also allows optimising the .* regexp) #7859
Description
What did you do?
I found that wildcard label matcher such as app=~".*" impact on query performance significantly.
Then i tried to edit benchmark BenchmarkPostingsForMatchers as followed,
The results is amazing!!!
The time consumption with wildcard is worser 100K times than without wildcard.
BenchmarkPostingsForMatchers/Head/n="1",i=~".*",j="foo"-16 5 213092008 ns/op
BenchmarkPostingsForMatchers/Head/n="1",j="foo"-16 593829 1838 ns/op
What did you expect to see?
Label matcher {n="1",i=~".*",j="foo} is equal to label matcher {n="1"j="foo}, so the evaluation cost should be similar.