checkbox for "Show other queries run during render" does nothing

$conf['dev_query'] was an old Drupal 6 variable, and it was removed when DBTNG was committed to core. It seems likely this feature has not ever worked on the D7 branches.

I tested the the patch in #3, and it did not restore the "show additional queries" functionality.

Wow, had no idea that so much info was not being output.

Patch applies clean, and indeed it is now showing me a LOT more queries that are being run.

The patch in #5 looks good to me. Tested with Views 7.x-3.7, displays many more queries when the box is checked and only the main query when it isn't.

Patch #5 applies fine, and works. Setting as RTBC, I'd love to see this get committed soon.

david_garcia_garcia: I agree the placeholder, caller, etc information is highly desirable. If you can improve this patch, great!

The devel module has a wonderful function for displaying this info: devel_query_table(). What I propose is using this function when it's available, rather than reimplementing another query log printer. When devel is unavailable, Views would fall back to a more simplistic display. The greatest advantage of devel_query_table() is it offers an AJAX interface for EXLAIN.

There is a problem however, devel_query_table() can't currently be used in this context, because it relies on a single shared Javascript value Drupal.settings.devel.request_id. I think it's a small change to convert the request ID to a DOM attribute, which then allows multiple query logs to be displayed within the same page.

So, my proposal is to commit an interim solution first, then work on improving devel_query_table(), then finally leveraging that function in Views.

+++ b/includes/admin.inc
@@ -186,33 +186,48 @@ function views_ui_preview($view, $display_id, $args = array()) {
+		    $query = $view->build_info['query'];

Stray tabs here, otherwise looks good. Can you please re-roll?

One more quibble, I'm seeing some notices with the latest patch:

Notice: Undefined variable: queries in views_ui_preview() (line 191 of sites/all/modules/views/includes/admin.inc).
Notice: Undefined variable: queries in views_ui_preview() (line 204 of sites/all/modules/views/includes/admin.inc).

All good, back to RTBC.

Checked how D8 does this:

/**
   * Set up query capturing.
   *
   * \Drupal\Core\Database\Database stores the queries that it runs, if logging
   * is enabled.
   *
   * @see ViewUI::endQueryCapture()
   */
  public function startQueryCapture() {
    Database::startLog('views');
  }

Timing is what it says on the D8 tin, 'during view rendering':

      if ($show_additional_queries) {
        $this->startQueryCapture();
      }

      // Execute/get the view preview.
      $preview = $executable->preview($display_id, $args);

      if ($show_additional_queries) {
        $this->endQueryCapture();
      }

So this should probably stay in the Views 7.x-3.x queue (and not the Drupal core queue for D8 Views). Moving it back to 7.x-3.x