disable focus for single token queries, use constant_score for ngrams matching

query/view/focus_selected_layers.js

@@ -14,6 +14,12 @@ var peliasQuery = require('pelias-query');
 module.exports = function( subview ){
   return function( vs ){
 
+    // don't perform this query on single character inputs
+    // as its too unperformant to sort a large part of the index.
+    if( vs.var('input:name').get().length < 2 ){
+      return null;
+    }
+
     if( !subview ){ return null; } // subview validation failed
     var macroView = peliasQuery.view.focus( subview );
     if( !macroView ){ return null; } // macroView validation failed

query/view/ngrams_last_token_only.js

@@ -28,5 +28,9 @@ module.exports = function( vs ){
   vsCopy.var('input:name').set( tokens.join(' ') );
 
   // return the view rendered using the copy
-  return ngrams_strict( vsCopy );
+  return {
+    'constant_score': {
+      'query': ngrams_strict( vsCopy )
+    }
+  };
 };

test/unit/fixture/autocomplete_linguistic_focus.js

@@ -3,6 +3,8 @@ module.exports = {
   'query': {
     'bool': {
       'must': [{
+        'constant_score': {
+          'query': {
             'match': {
               'name.default': {
                 'analyzer': 'peliasQueryPartialToken',
@@ -13,6 +15,8 @@ module.exports = {
                 'slop': 3
               }
             }
+          }
+        }
       }],
       'should': [{
         'function_score': {

test/unit/fixture/autocomplete_linguistic_focus_null_island.js

@@ -3,6 +3,8 @@ module.exports = {
   'query': {
     'bool': {
       'must': [{
+        'constant_score': {
+          'query': {
             'match': {
               'name.default': {
                 'analyzer': 'peliasQueryPartialToken',
@@ -13,6 +15,8 @@ module.exports = {
                 'slop': 3
               }
             }
+          }
+        }
       }],
       'should': [{
         'function_score': {

test/unit/fixture/autocomplete_linguistic_multiple_tokens.js

@@ -14,6 +14,8 @@ module.exports = {
         }
       },
       {
+        'constant_score': {
+          'query': {
             'match': {
               'name.default': {
                 'analyzer': 'peliasQueryPartialToken',
@@ -24,6 +26,8 @@ module.exports = {
                 'slop': 3
               }
             }
+          }
+        }
       }],
       'should':[
         {

test/unit/fixture/autocomplete_linguistic_only.js

@@ -3,6 +3,8 @@ module.exports = {
   'query': {
     'bool': {
       'must': [{
+        'constant_score': {
+          'query': {
             'match': {
               'name.default': {
                 'analyzer': 'peliasQueryPartialToken',
@@ -13,6 +15,8 @@ module.exports = {
                 'slop': 3
               }
             }
+          }
+        }
       }],
       'should':[{
         'function_score': {

test/unit/fixture/autocomplete_with_source_filtering.js

@@ -3,6 +3,8 @@ module.exports = {
   'query': {
     'bool': {
       'must': [{
+        'constant_score': {
+          'query': {
             'match': {
               'name.default': {
                 'analyzer': 'peliasQueryPartialToken',
@@ -13,6 +15,8 @@ module.exports = {
                 'slop': 3
               }
             }
+          }
+        }
       }],
       'should':[{
         'function_score': {