(In reply to comment #0)

In scribunto, a call to mw.title.new("page name") is very expensive.

{{citation needed}}

How is it "very expensive", and how would calculating CRCs and such improve matters?

Sorry, the function mw.title.new( id ) is "expensive" in the Lua manual.

Perhaps the cost is due to the search of the page by comparing full page names with others. In this case, to accelerate this comparing we could compare short int64 keys rather than full names. These keys could be computed like CRC polynoms from the full names.

Such keys change the sorting of pages, but this no matter because the goal is only "exists-or-no".

(In reply to comment #2)

Sorry, the function mw.title.new( id ) is "expensive" in the Lua manual.

Yes, that's because we don't want people doing thousands of database lookups to load (or check the existence of) thousands of title objects. Adding CRCs isn't going to change that, because it's the thousands of database round-trips we're wanting to avoid.