Add read_concurrency options to couch_server ETS

This adds the read_concurrency option to couch_server's ETS table for
couch_dbs which contains the references to open database handles. This
is an obvious improvement as all callers opening database pids interact
with this ETS table concurrently. Conversely, the couch_server pid is
the only writer, so no need for write_concurrency.
1 file changed