Understanding how the search function works

Unfortunately I have not found any documentation how the search function work. Therefore, I have to ask.

I simply entered an url in the search field (not advanced) like

http://www.example.org/category/page123.html

The result comes up after minutes of searching with

Showing 1 - 50 of 29234

But this is a little bit ugly, since only one ticket contains the exact url mentioned above.

If I start the search with double quote like

"http://www.example.org/category/page123.html"

the result comes up within a second showing 1 match as expected.

I guess without double quote, the search string is handled like a regular expression or something similar?