Corrections to Linked Database Documentation - ghrgriner/anki-stats GitHub Wiki

Below are corrections or clarifications to the database documentation in the ankidroid repository. These corrections are based on review of the Anki desktop application v25.02, and it's unclear whether they also apply to AnkiDroid.

The corrections / clarifications are:

• cards.data is no longer unused. This field is now a string in JSON format containing information about the FSRS scheduler where the 'd' item stores difficulty (to three decimal places), the 's' item stores stability (to three decimal places), and the 'dr' item stores desired retention. The FSRS retrievability is not stored in this field. It is calculated when needed using the difficulty, stability, and days elapsed since the review as input parameters.
• cards.due is a sequence number from a sequence starting at -100000 for cards moved into a filtered deck. (TBD: is this right, or is it for cards.position?)
• cards.queue takes value CardQueue::Review for cards moved into a filtered deck when rescheduling in the original deck is not selected.
• cards.ivl is never negative for the v3 scheduler (TBD: more info?)