new

# File activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb, line 117
        def initialize(...)
          super
          @query_cache_version = Concurrent::AtomicFixnum.new
          @thread_query_caches = QueryCacheRegistry.new
          @query_cache_max_size =              case query_cache = db_config&.query_cache
            when 0, false
              nil
            when Integer
              query_cache
            when nil
              DEFAULT_SIZE
            end
        end