Support automattic aggregation only when aggregation para is set to 'auto'

lib/cartodb/backends/dataview.js

@@ -21,6 +21,7 @@ function DataviewBackend(analysisBackend) {
 }
 
 var DATE_AGGREGATIONS = {
+    'auto': true,
     'minute': true,
     'hour': true,
     'day': true,

lib/cartodb/models/dataview/histogram.js

@@ -5,6 +5,8 @@ var debug = require('debug')('windshaft:dataview:histogram');
 var dot = require('dot');
 dot.templateSettings.strip = false;
 
+var columnCastTpl = dot.template("date_part('epoch', {{=it.column}})");
+
 var dateIntervalQueryTpl = dot.template([
     'WITH',
     'dates AS (',
@@ -331,10 +333,14 @@ Histogram.prototype._buildQuery = function (psql, override, callback) {
     var _column = this.column;
     var _query = this.query;
 
-    if (this._columnType === 'date') {
+    if (this._columnType === 'date' && this.aggregation !== undefined) {
         return this._buildDateHistogramQuery(psql, override, callback);
     }
 
+    if (this._columnType === 'date') {
+        _column = columnCastTpl({column: _column});
+    }
+
     filteredQuery = filteredQueryTpl({
         _isFloatColumn: this._columnType === 'float',
         _query: _query,
@@ -434,7 +440,7 @@ Histogram.prototype._buildDateHistogramQuery = function (psql, override, callbac
     var _aggregation = override && override.aggregation ? override.aggregation : this.aggregation;
     var _offset = override && Number.isFinite(override.offset) ? override.offset : this.offset;
 
-    if (!_aggregation) {
+    if (_aggregation === 'auto') {
         this.getAutomaticAggregation(psql, function (err, aggregation) {
             if (err || aggregation === 'none') {
                 this.aggregation = 'day';

test/acceptance/dataviews/histogram.js

@@ -160,7 +160,8 @@ describe('histogram-dataview for date column type', function() {
                 },
                 type: 'histogram',
                 options: {
-                    column: 'd'
+                    column: 'd',
+                    aggregation: 'auto'
                 }
             },
             date_histogram: {
@@ -179,7 +180,8 @@ describe('histogram-dataview for date column type', function() {
                 },
                 type: 'histogram',
                 options: {
-                    column: 'd'
+                    column: 'd',
+                    aggregation: 'auto'
                 }
             },
             minute_histogram: {