I have several classic movie/western channels with large time blocks to balance the small show sub channels out.
The cablelabs spec employed in xml even with thumbnails and previews covering 1028160 minutes of programming wouldn't take 3 hours to complete a download, extract, and database load. There's gotta be something going on.
Seriously.. a movie needs at most about 100K of data for meta info and thumbnail. If we assume every channel only does 30 minute segments that equates to 34272 possible shows. If we assume absolute worst case of zero re-runs and all original content in every single time slot possible (no series) then we take 100K per asset (30 minute show per timeslot).. that's a total of 3.5GB to download and process.
Convert the actual 3427200KB of data from bytes to bits and we're at 27417600Kb.. spread that across a 3 hour window for download and we should be pulling at least 2.5Mbps of network traffic for a full guide which is child's play for on demand video streaming.
Guide is at 90% and we're now over 4 hours though so the actual rate is much lower than the above figures. This tells me something is grossly wrong with guide data transfer and Tablo ingest.