Missing indexes for sensor name and timestamp

+++ b/monitoring.install
@@ -57,8 +57,25 @@ function monitoring_schema() {
+ */
+function monitoring_update_7001() {
+  try {
+    db_add_index('monitoring_sensor_result', 'timestamp', array('timestamp'));
+  }
+  catch (DatabaseSchemaObjectExistsException $exception) {
+    watchdog('monitoring', 'The timestamp index already exists.');
+  }
+  catch (Exception $exception) {
+    watchdog('monitoring', $exception->getMessage(), WATCHDOG_ERROR);
+    throw new DrupalUpdateException($exception->getMessage());
+  }

the index already existing check can be verified first, then you don't need that catch. also imho it is very unlikely to fail when checking that we and we could just leave the try/catch out.. update process catches every exception and reports them, I never do that in my own update functions.

Rediscovered this on D8 as well, but just timestamp isn't enough, needs an index with sensor name as well.

This drops the cost of monitoring_sensor_result_last() from 1.4s to 50ms for me on 11.3 and 11.4 will hopefully improve it further with improved entity queries.

Merged.