Revert "Fix json index selection (apache#816)"

This reverts commit dae81be.

Conflicts:
	src/mango/test/05-index-selection-test.py

src/mango/src/mango_idx_view.erl

@@ -115,12 +115,11 @@ columns(Idx) ->
 
 
 is_usable(Idx, Selector) ->
-    % This index is usable if all of the columns are 
-    % restricted by the selector such that they are required to exist
-    % and the selector is not a text search (so requires a text index)
-    RequiredFields = columns(Idx),
-    mango_selector:has_required_fields(Selector, RequiredFields)
-        andalso not is_text_search(Selector).
+    % This index is usable if at least the first column is
+    % a member of the indexable fields of the selector.
+    Columns = columns(Idx),
+    Fields = indexable_fields(Selector),
+    lists:member(hd(Columns), Fields) andalso not is_text_search(Selector).
 
 
 is_text_search({[]}) ->

src/mango/src/mango_selector.erl

@@ -15,8 +15,7 @@
 
 -export([
     normalize/1,
-    match/2,
-    has_required_fields/2
+    match/2
 ]).
 
 
@@ -567,110 +566,3 @@ match({[{Field, Cond}]}, Value, Cmp) ->
 
 match({[_, _ | _] = _Props} = Sel, _Value, _Cmp) ->
     erlang:error({unnormalized_selector, Sel}).
-
-
-% Returns true if Selector requires all  
-% fields in RequiredFields to exist in any matching documents.
-
-% For each condition in the selector, check
-% whether the field is in RequiredFields.
-% If it is, remove it from RequiredFields and continue
-% until we match then all or run out of selector to
-% match against.
-
-% Empty selector
-has_required_fields({[]}, _) ->
-    false;
-
-% No more required fields
-has_required_fields(_, []) ->
-    true;
-
-% No more selector
-has_required_fields([], _) ->
-    false;
-
-has_required_fields(Selector, RequiredFields) when not is_list(Selector) ->
-    has_required_fields([Selector], RequiredFields);
-
-% We can "see" through $and operator. We ignore other
-% combination operators because they can't be used to restrict
-% an index.
-has_required_fields([{[{<<"$and">>, Args}]}], RequiredFields) 
-        when is_list(Args) ->
-    has_required_fields(Args, RequiredFields);
-
-has_required_fields([{[{Field, Cond}]} | Rest], RequiredFields) ->
-    case Cond of
-        % $exists:false is a special case - this is the only operator
-        % that explicitly does not require a field to exist
-        {[{<<"$exists">>, false}]} ->
-            has_required_fields(Rest, RequiredFields);
-        _ ->
-            has_required_fields(Rest, lists:delete(Field, RequiredFields))
-    end.
-
-
-%%%%%%%% module tests below %%%%%%%%
-
--ifdef(TEST).
--include_lib("eunit/include/eunit.hrl").
-
-has_required_fields_basic_test() ->
-    RequiredFields = [<<"A">>],
-    Selector = {[{<<"A">>, <<"foo">>}]},
-    Normalized = normalize(Selector),
-    ?assertEqual(true, has_required_fields(Normalized, RequiredFields)).
-
-has_required_fields_basic_failure_test() ->
-    RequiredFields = [<<"B">>],
-    Selector = {[{<<"A">>, <<"foo">>}]},
-    Normalized = normalize(Selector),
-    ?assertEqual(false, has_required_fields(Normalized, RequiredFields)).
-
-has_required_fields_empty_selector_test() ->
-    RequiredFields = [<<"A">>],
-    Selector = {[]},
-    Normalized = normalize(Selector),
-    ?assertEqual(false, has_required_fields(Normalized, RequiredFields)).
-
-has_required_fields_exists_false_test() ->
-    RequiredFields = [<<"A">>],
-    Selector = {[{<<"A">>,{[{<<"$exists">>, false}]}}]},
-    Normalized = normalize(Selector),
-    ?assertEqual(false, has_required_fields(Normalized, RequiredFields)).
-
-has_required_fields_and_true_test() ->
-    RequiredFields = [<<"A">>],
-    Selector = {[{<<"$and">>,
-          [
-              {[{<<"A">>, <<"foo">>}]},
-              {[{<<"B">>, <<"foo">>}]}
-          ]
-    }]},
-    Normalized = normalize(Selector),
-    ?assertEqual(true, has_required_fields(Normalized, RequiredFields)).
-
-has_required_fields_and_false_test() ->
-    RequiredFields = [<<"A">>, <<"C">>],
-    Selector = {[{<<"$and">>,
-          [
-              {[{<<"A">>, <<"foo">>}]},
-              {[{<<"B">>, <<"foo">>}]}
-          ]
-    }]},
-    Normalized = normalize(Selector),
-    ?assertEqual(false, has_required_fields(Normalized, RequiredFields)).
-
-has_required_fields_or_test() ->
-    RequiredFields = [<<"A">>],
-    Selector = {[{<<"$or">>,
-          [
-              {[{<<"A">>, <<"foo">>}]},
-              {[{<<"B">>, <<"foo">>}]}
-          ]
-    }]},
-    Normalized = normalize(Selector),
-    ?assertEqual(false, has_required_fields(Normalized, RequiredFields)).
-
--endif.

src/mango/test/03-operator-test.py

@@ -26,8 +26,8 @@ def test_all(self):
                 "manager": True,
                 "favorites": {"$all": ["Lisp", "Python"]}
             })
-        self.assertEqual(len(docs), 3)
-        user_ids = [2,12,9]
+        self.assertEqual(len(docs), 4)
+        user_ids = [2,12,9,14]
         self.assertUserIds(user_ids, docs)
 
     def test_all_non_array(self):
@@ -124,7 +124,7 @@ def test_in_operator_array(self):
                 "manager": True,
                 "favorites": {"$in": ["Ruby", "Python"]}
             })
-        self.assertUserIds([2,6,7,9,11,12], docs)
+        self.assertUserIds([2,6,7,9,11,12,14], docs)
 
     def test_nin_operator_array(self):
         docs = self.db.find({

src/mango/test/05-index-selection-test.py

@@ -18,7 +18,7 @@
 class IndexSelectionTests:
 
     def test_basic(self):
-        resp = self.db.find({"age": 123}, explain=True)
+        resp = self.db.find({"name.last": "A last name"}, explain=True)
         self.assertEqual(resp["index"]["type"], "json")
 
     def test_with_and(self):
@@ -63,48 +63,6 @@ def test_invalid_use_index(self):
         else:
             raise AssertionError("bad find")
 
-    def test_uses_index_when_no_range_or_equals(self):
-        # index on ["manager"] should be valid because
-        # selector requires "manager" to exist. The
-        # selector doesn't narrow the keyrange so it's
-        # a full index scan
-        selector = {
-            "manager": {"$exists": True}
-        }
-        docs = self.db.find(selector)
-        self.assertEqual(len(docs), 14)
-
-        resp_explain = self.db.find(selector, explain=True)
-        self.assertEqual(resp_explain["index"]["type"], "json")
-
-
-    def test_reject_use_index_invalid_fields(self):
-        # index on ["company","manager"] which should not be valid
-        ddocid = "_design/a0c425a60cf3c3c09e3c537c9ef20059dcef9198"
-        selector = {
-            "company": "Pharmex"
-        }
-        try:
-            self.db.find(selector, use_index=ddocid)
-        except Exception as e:
-            self.assertEqual(e.response.status_code, 400)
-        else:
-            raise AssertionError("did not reject bad use_index")
-
-    def test_reject_use_index_sort_order(self):
-        # index on ["company","manager"] which should not be valid
-        ddocid = "_design/a0c425a60cf3c3c09e3c537c9ef20059dcef9198"
-        selector = {
-            "company": {"$gt": None},
-            "manager": {"$gt": None}
-        }
-        try:
-            self.db.find(selector, use_index=ddocid, sort=[{"manager":"desc"}])
-        except Exception as e:
-            self.assertEqual(e.response.status_code, 400)
-        else:
-            raise AssertionError("did not reject bad use_index")
-
     # This doc will not be saved given the new ddoc validation code
     # in couch_mrview
     def test_manual_bad_view_idx01(self):
@@ -159,7 +117,7 @@ def test_uses_all_docs_when_fields_do_not_match_selector(self):
         self.assertEqual(len(docs), 1)
         self.assertEqual(docs[0]["company"], "Pharmex")
         self.assertNotIn("manager", docs[0])
-        
+
         resp_explain = self.db.find(selector, explain=True)
 
         self.assertEqual(resp_explain["index"]["type"], "special")
@@ -211,7 +169,7 @@ def test_with_or(self):
                 ]
             }, explain=True)
         self.assertEqual(resp["index"]["type"], "text")
-    
+
     def test_manual_bad_text_idx(self):
         design_doc = {
             "_id": "_design/bad_text_index",

src/mango/test/user_docs.py

@@ -493,6 +493,7 @@ def add_text_indexes(db, kwargs):
         },
         "company": "Pharmex",
         "email": "[email protected]",
+        "manager": True,
         "favorites": [
             "Erlang",
             "Python",