"What the latest bugged EX wave teaches us about PoGO database structure"

#PokemonGO: So, this morning (in Australia) some trainers woke up to find an EX pass to a raid starting on the same day in 15-20 minutes. Upon arriving to the gym they discovered a pink egg which indeed hatched a Magneton. Reportedly they were even able to use their EX pass to fight Magneton. After the raid finished the EX pass remained in storage; the date auto-updated to October 2(UPDATE: reportedly the raid was canceled despite Niantic support claiming it would auto-update. This further proves the below theory).This all would only make sense if the database was architected like this:Gyms. All raid details are stored directly in the "gyms" table, so a gym can either have no raid or have a hatching/ongoing raid; it's not possible to schedule a raid "after the current one":gyms_table ... raid_hatch_time raid_expiry_time raid_boss Passes. The EX raid passes do not store raid details, they only store which trainer was invited to which gym (and possibly an expiry date after which the pass needs to be deleted):ex_passes_table gym_id trainer_id expiry_date When viewing the EX pass in the app all the details are coming from the hatching/ongoing raid in the gym.With the above database structure it becomes obvious why things behave like they are:"Invisible egg" theory is true - it was theorized that after issuing EX passes the gym has an "invisible EX egg" on it and this is why there are no raids happening. Indeed, it is not possible to spawn a raid on the EX gym without canceling the EX raid. This is not a gameplay element, it's a limitation of the database structure.Clock-blocking theory is true - it is not possible to schedule an EX raid if the gym has an ongoing raid, without canceling the ongoing raid. It appears that previously their "ex pass script" had a safeguard to simply skip gyms with an ongoing raid (or maybe it was simply crashing), but now it does send the passes, which for some time display the details of the ongoing raid.UPDATE: There are reports of the gyms which sent out EX passes to continue spawning "normal" raids, and reportedly those raids do not cancel/erase the EX passes, to it looks like Niantic has made some improvements and the above description no longer applies. Clockblocking and "invisible egg" may be things of the past. via /r/TheSilphRoad https://ift.tt/2NNE1y8