Task History Compression

Habitica has history features to help you track your progress. The following information is stored as it changes over time:
* task values of your Dailies and Habits 
* total task value of all your To Do's
* your experience
To improve performance of the website and mobile apps (Android and iOS), and to reduce database storage costs, Habitica does not keep all historical data for all tasks. Instead, older data is averaged and only the average is included in the data exports. The further back in time the data goes, the more data is combined together into a single average. This compression of data works differently for subscribers and non-subscribers.
Habitica also removes completed To Do's after a certain time.
==For Non-Subscribers==
History is represented by one value for each day for the previous 60 days. Beyond that, task history is compressed to one value each month for the previous 10 months, and then one value each year for the previous years.
For example, on January 1, 2016, a non-subscriber would have uncompressed history going back to November 2, 2015. After that, they'd have ten averages, one each for the months of January 2015-October 2015, and then one average each for the entire years of 2014 and 2013, respectively.
Completed To Do's are deleted 30 days after they were marked completed. However, if a player uses the "Delete Completed" button in the To Do's' Completed tab, all completed To Do's are permanently removed immediately. To learn how to view all completed To Do's before deletion, refer to the "Completing a To Do" section in To Do's.
==For Subscribers==
History is represented by one value for each day for the previous 365 days. Beyond that, history is compressed to one value each month for the previous 12 months, and then one value each year for the previous years.
For example, on January 1, 2016, a subscriber would have uncompressed history going back to January 1, 2015. After that, they'd have twelve entries, one each for the months of January 2014 to December 2014, and then one entry each for the entire year of 2013.
Completed To Do's are deleted 90 days after they were marked completed. However, if a player uses the "Delete Completed" button in the To Do's' Completed tab, all completed To Do's are permanently removed immediately. To learn how to view all completed To Do's before deletion, refer to the "Completing a To Do" section in To Do's.
==Changes in Subscription Status==
When a subscriber's subscription ends without being renewed, the extra task history will be lost. If the subscription is renewed in future, the lost task history cannot be retrieved.
When a non-subscriber becomes a subscriber, additional task history and completed To Do's will start being saved from that time forward. Task history and completed To Do's from before the subscription started will not be available.
fr:Compression de l'historique des tâches
ru:Сжатие истории задач
zh:任务历史压缩
Category:Content