A few thoughts occurred to me today about our indexing code:
1) we compute a hash preset for each invocation, crunching the syntax
and matching rule's OID, among other things. (It used to be worse, we
used to recompute this for each individual value, even though it's a
constant.) There's no need to always recompute this on each invocation,
we can compute it once at first usage and reuse that result. It should
speed up index generation, particularly on smaller attribute values. I'm
preparing a patch to test this now.
2) using this precomputed hash, we can drop the syntax, mr, and prefix
arguments from the indexer function signature. That will also speed
things up.
3) I note that the 'use' argument is also never used in our indexer
functions. Will drop this as well.