This is a simple naming change PR, to fix the fact that "metadata" is a
single English word, and for too long we have not followed general
naming conventions for it. We are also not consistent about it, for
example, METADATA instead of META_DATA if we were trying to be
consistent with MetaData (although METADATA is correct when considered
in the context of "metadata"). This was a simple find and replace across
the code base, only taking a few minutes to fix this naming issue
forever.
* New wildcard field optimised for wildcard queries (#49993)
Indexes values using size 3 ngrams and also stores the full original as a binary doc value.
Wildcard queries operate by using a cheap approximation query on the ngram field followed up by a more expensive verification query using an automaton on the binary doc values. Also supports aggregations and sorting.