diff --git a/lib/ransack/adapters/active_record/3.0/context.rb b/lib/ransack/adapters/active_record/3.0/context.rb
index e725a2cdf..1d5ffd23e 100644
--- a/lib/ransack/adapters/active_record/3.0/context.rb
+++ b/lib/ransack/adapters/active_record/3.0/context.rb
@@ -44,7 +44,7 @@ def attribute_method?(str, klass = @klass)
 
           if ransackable_attribute?(str, klass)
             exists = true
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while !found_assoc && remainder.unshift(segments.pop) &&
@@ -98,7 +98,7 @@ def get_parent_and_attribute_name(str, parent = @base)
 
           if ransackable_attribute?(str, klassify(parent))
             attr_name = str
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while remainder.unshift(segments.pop) && segments.size > 0 &&
diff --git a/lib/ransack/adapters/active_record/3.1/context.rb b/lib/ransack/adapters/active_record/3.1/context.rb
index 8a9cbdc07..719098f3e 100644
--- a/lib/ransack/adapters/active_record/3.1/context.rb
+++ b/lib/ransack/adapters/active_record/3.1/context.rb
@@ -38,7 +38,7 @@ def attribute_method?(str, klass = @klass)
 
           if ransackable_attribute?(str, klass)
             exists = true
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while !found_assoc && remainder.unshift(segments.pop) &&
@@ -105,7 +105,7 @@ def get_parent_and_attribute_name(str, parent = @base)
 
           if ransackable_attribute?(str, klassify(parent))
             attr_name = str
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while remainder.unshift(segments.pop) && segments.size > 0 &&
diff --git a/lib/ransack/adapters/active_record/base.rb b/lib/ransack/adapters/active_record/base.rb
index 6975e80bd..bed853524 100644
--- a/lib/ransack/adapters/active_record/base.rb
+++ b/lib/ransack/adapters/active_record/base.rb
@@ -32,7 +32,7 @@ def ransack_alias(new_name, old_name)
         # For overriding with a whitelist array of strings.
         #
         def ransackable_attributes(auth_object = nil)
-          if Ransack::SUPPORTS_ATTRIBUTE_ALIAS
+          @ransackable_attributes ||= if Ransack::SUPPORTS_ATTRIBUTE_ALIAS
             column_names + _ransackers.keys + _ransack_aliases.keys +
             attribute_aliases.keys
           else
@@ -45,7 +45,7 @@ def ransackable_attributes(auth_object = nil)
         # For overriding with a whitelist array of strings.
         #
         def ransackable_associations(auth_object = nil)
-          reflect_on_all_associations.map { |a| a.name.to_s }
+          @ransackable_associations ||= reflect_on_all_associations.map { |a| a.name.to_s }
         end
 
         # Ransortable_attributes, by default, returns the names
diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 07477175d..235b73809 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -45,7 +45,7 @@ def attribute_method?(str, klass = @klass)
           exists = false
           if ransackable_attribute?(str, klass)
             exists = true
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while !found_assoc && remainder.unshift(segments.pop) &&
@@ -268,7 +268,8 @@ def build_joins(relation)
           association_joins         = buckets[:association_join]
           stashed_association_joins = buckets[:stashed_join]
           join_nodes                = buckets[:join_node].uniq
-          string_joins              = buckets[:string_join].map(&:strip).uniq
+          string_joins              = buckets[:string_join].map(&:strip)
+          string_joins.uniq!
 
           join_list =
             if ::ActiveRecord::VERSION::MAJOR >= 5
@@ -295,10 +296,9 @@ def build_joins(relation)
         end
 
         def convert_join_strings_to_ast(table, joins)
+          joins.map! { |join| table.create_string_join(Arel.sql(join)) unless join.blank? }
+          joins.compact!
           joins
-          .flatten
-          .reject(&:blank?)
-          .map { |join| table.create_string_join(Arel.sql(join)) }
         end
 
         def build_or_find_association(name, parent = @base, klass = nil)
diff --git a/lib/ransack/adapters/active_record/ransack/context.rb b/lib/ransack/adapters/active_record/ransack/context.rb
index 708efeaa2..68f35f205 100644
--- a/lib/ransack/adapters/active_record/ransack/context.rb
+++ b/lib/ransack/adapters/active_record/ransack/context.rb
@@ -37,15 +37,14 @@ def initialize(object, options = {})
         @base = @join_dependency.join_base
         @engine = @base.arel_engine
       end
+    end
 
-      @default_table = Arel::Table.new(
-        @base.table_name, as: @base.aliased_table_name, type_caster: self
-        )
-      @bind_pairs = Hash.new do |hash, key|
-        parent, attr_name = get_parent_and_attribute_name(key)
-        if parent && attr_name
-          hash[key] = [parent, attr_name]
-        end
+    def bind_pair_for(key)
+      @bind_pairs ||= {}
+
+      @bind_pairs[key] ||= begin
+        parent, attr_name = get_parent_and_attribute_name(key.to_s)
+        [parent, attr_name] if parent && attr_name
       end
     end
 
diff --git a/lib/ransack/adapters/mongoid/context.rb b/lib/ransack/adapters/mongoid/context.rb
index f1a1db41f..3ca2ebeb9 100644
--- a/lib/ransack/adapters/mongoid/context.rb
+++ b/lib/ransack/adapters/mongoid/context.rb
@@ -34,7 +34,7 @@ def type_for(attr)
 
           name = '_id' if name == 'id'
 
-          t = object.klass.fields[name].try(:type) || @bind_pairs[attr.name].first.fields[name].type
+          t = object.klass.fields[name].try(:type) || bind_pair_for(attr.name).first.fields[name].type
 
           t.to_s.demodulize.underscore.to_sym
         end
@@ -61,7 +61,7 @@ def attribute_method?(str, klass = @klass)
           exists = false
           if ransackable_attribute?(str, klass)
             exists = true
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while !found_assoc && remainder.unshift(
@@ -111,7 +111,7 @@ def get_parent_and_attribute_name(str, parent = @base)
 
           if ransackable_attribute?(str, klassify(parent))
             attr_name = str
-          elsif (segments = str.split(/_/)).size > 1
+          elsif (segments = str.split(Constants::UNDERSCORE)).size > 1
             remainder = []
             found_assoc = nil
             while remainder.unshift(
diff --git a/lib/ransack/adapters/mongoid/ransack/context.rb b/lib/ransack/adapters/mongoid/ransack/context.rb
index bba2b5072..4767dcbc3 100644
--- a/lib/ransack/adapters/mongoid/ransack/context.rb
+++ b/lib/ransack/adapters/mongoid/ransack/context.rb
@@ -30,15 +30,14 @@ def initialize(object, options = {})
 
       @base = @object.klass
       # @engine = @base.arel_engine
+    end
+
+    def bind_pair_for(key)
+      @bind_pairs ||= {}
 
-      # @default_table = Arel::Table.new(
-      #   @base.table_name, :as => @base.aliased_table_name, :engine => @engine
-      #   )
-      @bind_pairs = Hash.new do |hash, key|
+      @bind_pairs[key] ||= begin
         parent, attr_name = get_parent_and_attribute_name(key.to_s)
-        if parent && attr_name
-          hash[key] = [parent, attr_name]
-        end
+        [parent, attr_name] if parent && attr_name
       end
     end
 
diff --git a/lib/ransack/configuration.rb b/lib/ransack/configuration.rb
index 51d9048fa..498cd2b7f 100644
--- a/lib/ransack/configuration.rb
+++ b/lib/ransack/configuration.rb
@@ -5,7 +5,27 @@ module Ransack
   module Configuration
 
     mattr_accessor :predicates, :options
-    self.predicates = {}
+
+    class PredicateCollection
+      attr_reader :sorted_names_with_underscores
+
+      def initialize
+        @collection = {}
+        @sorted_names_with_underscores = []
+      end
+
+      delegate :[], :keys, to: :@collection
+
+      def []=(key, value)
+        @sorted_names_with_underscores << [key, '_' + key]
+        @sorted_names_with_underscores.sort! { |(a, _), (b, _)| b.length <=> a.length }
+
+        @collection[key] = value
+      end
+    end
+
+    self.predicates = PredicateCollection.new
+
     self.options = {
       :search_key => :q,
       :ignore_unknown_conditions => true,
diff --git a/lib/ransack/context.rb b/lib/ransack/context.rb
index cc2efa9d0..494fa4d63 100644
--- a/lib/ransack/context.rb
+++ b/lib/ransack/context.rb
@@ -40,7 +40,7 @@ def klassify(obj)
     # Convert a string representing a chain of associations and an attribute
     # into the attribute itself
     def contextualize(str)
-      parent, attr_name = @bind_pairs[str]
+      parent, attr_name = bind_pair_for(str)
       table_for(parent)[attr_name]
     end
 
@@ -59,24 +59,24 @@ def scope_arity(scope)
 
     def bind(object, str)
       return nil unless str
-      object.parent, object.attr_name = @bind_pairs[str]
+      object.parent, object.attr_name = bind_pair_for(str)
     end
 
     def traverse(str, base = @base)
       str ||= ''.freeze
 
-      if (segments = str.split(/_/)).size > 0
+      if (segments = str.split(Constants::UNDERSCORE)).size > 0
         remainder = []
         found_assoc = nil
         while !found_assoc && segments.size > 0 do
           # Strip the _of_Model_type text from the association name, but hold
           # onto it in klass, for use as the next base
           assoc, klass = unpolymorphize_association(
-            segments.join('_'.freeze)
+            segments.join(Constants::UNDERSCORE)
             )
           if found_assoc = get_association(assoc, base)
             base = traverse(
-              remainder.join('_'.freeze), klass || found_assoc.klass
+              remainder.join(Constants::UNDERSCORE), klass || found_assoc.klass
               )
           end
 
@@ -93,9 +93,9 @@ def association_path(str, base = @base)
       base = klassify(base)
       str ||= ''.freeze
       path = []
-      segments = str.split(/_/)
+      segments = str.split(Constants::UNDERSCORE)
       association_parts = []
-      if (segments = str.split(/_/)).size > 0
+      if (segments = str.split(Constants::UNDERSCORE)).size > 0
         while segments.size > 0 &&
         !base.columns_hash[segments.join(Constants::UNDERSCORE)] &&
         association_parts << segments.shift do
@@ -135,7 +135,7 @@ def ransackable_association?(str, klass)
     end
 
     def ransackable_scope?(str, klass)
-      klass.ransackable_scopes(auth_object).any? { |s| s.to_s == str }
+      klass.ransackable_scopes(auth_object).any? { |s| s.to_sym == str.to_sym }
     end
 
     def searchable_attributes(str = ''.freeze)
diff --git a/lib/ransack/nodes/grouping.rb b/lib/ransack/nodes/grouping.rb
index 5f6746e2f..bab036cdb 100644
--- a/lib/ransack/nodes/grouping.rb
+++ b/lib/ransack/nodes/grouping.rb
@@ -191,7 +191,7 @@ def read_attribute(name)
       end
 
       def strip_predicate_and_index(str)
-        string = str.split(/\(/).first
+        string = str[/(.+?)\(/, 1] || str
         Predicate.detect_and_strip_from_string!(string)
         string
       end
diff --git a/lib/ransack/predicate.rb b/lib/ransack/predicate.rb
index 935729469..ff7be7ac4 100644
--- a/lib/ransack/predicate.rb
+++ b/lib/ransack/predicate.rb
@@ -9,34 +9,26 @@ def names
         Ransack.predicates.keys
       end
 
-      def names_by_decreasing_length
-        names.sort { |a, b| b.length <=> a.length }
-      end
-
       def named(name)
         Ransack.predicates[name.to_s]
       end
 
       def detect_and_strip_from_string!(str)
-        if p = detect_from_string(str)
-          str.sub! /_#{p}$/, ''.freeze
-          p
-        end
+        detect_from_string str, chomp: true
       end
 
-      def detect_from_string(str)
-        names_by_decreasing_length.detect { |p| str.end_with?("_#{p}") }
-      end
+      def detect_from_string(str, chomp: false)
+        return unless str
 
-#      def name_from_attribute_name(attribute_name)
-#        names_by_decreasing_length.detect {
-#          |p| attribute_name.to_s.match(/_#{p}$/)
-#        }
-#      end
+        Ransack.predicates.sorted_names_with_underscores.each do |predicate, underscored|
+          if str.end_with? underscored
+            str.chomp! underscored if chomp
+            return predicate
+          end
+        end
 
-#      def for_attribute_name(attribute_name)
-#        self.named(detect_from_string(attribute_name.to_s))
-#      end
+        nil
+      end
 
     end
 
diff --git a/lib/ransack/translate.rb b/lib/ransack/translate.rb
index 93821ddd6..178b0a936 100644
--- a/lib/ransack/translate.rb
+++ b/lib/ransack/translate.rb
@@ -24,8 +24,8 @@ def self.attribute(key, options = {})
       base_ancestors = base_class.ancestors.select {
         |x| x.respond_to?(:model_name)
       }
-      predicate = Predicate.detect_from_string(original_name)
-      attributes_str = original_name.sub(/_#{predicate}$/, ''.freeze)
+      attributes_str = original_name.dup # will be modified by ⬇
+      predicate = Predicate.detect_and_strip_from_string!(attributes_str)
       attribute_names = attributes_str.split(/_and_|_or_/)
       combinator = attributes_str.match(/_and_/) ? :and : :or
       defaults = base_ancestors.map do |klass|