It's a definite duplicated alarms. Cyclops alerts are based on 3 set of coords which their proprietary code handled. SCDB (or Garmin POI-like) alerts are based on one. So the chances they are "exactly" the same is slim.
If you go with the mentality that any alert is better than no alert (ie: coverage) then use both. If you only wants accuracy (but not necessary the "latest" addition), then go with Cyclops*. People uses SCDB because it's freely available and updated often (but not necessary correct nor accurate)

* Cyclops is a pay service; if you use it, please try to buy it