I'm posting this as a helpful hint regarding making REST calls and having refreshed data show up. We worked with our partner this past week, Made Media, to get this working and in the end, it was a Tessitura help ticket that helped us resolve it. They also marked it as a defect to be addressed later on but I hope that by posting this here, we can save someone a headache in the future.
Part of our work caused an entry into TR_DATASERVICE_TABLES to be made. That was normal and expected. We noticed two sets of duplicate records though, so we deleted them from the table. The table showed 4 records via a SQL query and from within the Tessitura application. No matter what we did, the changes would not show up in the REST call. We continued to show 6 records there. This was on Tuesday.
On Wednesday morning, we decided to test again to see if the issue resolved overnight. It had but only because the REST application pool recycles at 4 AM every morning for us. We had opened a ticket with Tessitura and they had us do a test. We made another entry into TR_DATASERVICE_TABLES, refreshed the REST call to make sure it didn't show up, then recycled the REST application pool and refreshed the REST call. Once we did that, the new entry showed up.
Long story short, if you're using a REST call and things aren't showing up, recycle your REST application pool and refresh. That'll likely fix it.