[Kobo] Is there a way to disable database writes? - Page 2

Lucas Malor · 07-29-2014, 07:39 AM

Eheh this is the hilarious part... I had to reset my kobo few weeks ago and I forgot to reinstall my backup script

Luckily I was able to extract the Bookmarks table, that is the most important thing for me (by the way, I think I'll add an option to backup only that table. For me is enough).

Yes, calibre did not report any error. But I noticed the corruption when I rebooted the device, not when I disconnected it. This is why I supposed it's nickel itself. Or maybe a coincidence.

Next time I'll backup the database before any calibre operation. If a corruption happens, I'll reboot calibre in debug mode and I'll redo the operations.

Lucas Malor · 08-03-2014, 09:49 AM

Ok, I copied the entire content of my internal sd card before deleting a book (with Kobo, not with Calibre), and then I checked for differences.
It *seems* that the db does not change in any useful table (the only affected table is the one that stores analytic data). This is quite surprising. It *seems* that the only difference is that not only the book, but also book cover images are removed from the device.

Calibre seems to remove cover images as well, since they are no more displayed in tiles. Do you know if it removes the subfolder that contains the images? Kobo does not remove the subfolders.

davidfor · 08-03-2014, 10:59 PM

When a book is deleted from a Kobo device using the calibre, the following is done:

- Update the database to remove appropriate rows from tables: content, content_settings, ShelfContent, ratings, Activity, shortcover_page, content_keys.
- The cover images are deleted and the folder is removed if it is empty.
- The book is deleted and the folder is removed if it is empty.

From my tests, this is the same as when the device does the deleting except the empty folders are not removed.

Lucas Malor · 08-04-2014, 06:35 AM

It's strange that I had no modification in the Activity table. Anyway, the folder removal is not a problem, since I removed it manually and nothing happened. I think I have to wait until I have to remove something with Calibre

davidfor · 08-04-2014, 07:31 AM

The Activity table is used for the tiles on the home screen. If the book hasn't been opened, it is likely that there is no Activity row for the book.

Lucas Malor · 08-06-2014, 08:18 AM

Ok, it rehappened. This time I've not removed books, but added some of them. After reboot, some books had broken tiles and new books were missing.

I've done a soft reset and tried to reproduce the problem, with calibre in debug mode this time. Nothing happened. It seems the issue is not reproducible, so I'll always start calibre in debug mode from now, logging the output.

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07-29-2014, 07:39 AM	#16
Lucas Malor Pain in the arse Posts: 758 Karma: 77856 Join Date: Apr 2013 Device: Kobo Aura One, Kindle 4	Eheh this is the hilarious part... I had to reset my kobo few weeks ago and I forgot to reinstall my backup script Luckily I was able to extract the Bookmarks table, that is the most important thing for me (by the way, I think I'll add an option to backup only that table. For me is enough). Yes, calibre did not report any error. But I noticed the corruption when I rebooted the device, not when I disconnected it. This is why I supposed it's nickel itself. Or maybe a coincidence. Next time I'll backup the database before any calibre operation. If a corruption happens, I'll reboot calibre in debug mode and I'll redo the operations.

08-03-2014, 09:49 AM	#17
Lucas Malor Pain in the arse Posts: 758 Karma: 77856 Join Date: Apr 2013 Device: Kobo Aura One, Kindle 4	Ok, I copied the entire content of my internal sd card before deleting a book (with Kobo, not with Calibre), and then I checked for differences. It seems that the db does not change in any useful table (the only affected table is the one that stores analytic data). This is quite surprising. It seems that the only difference is that not only the book, but also book cover images are removed from the device. Calibre seems to remove cover images as well, since they are no more displayed in tiles. Do you know if it removes the subfolder that contains the images? Kobo does not remove the subfolders.

08-03-2014, 10:59 PM	#18
davidfor Grand Sorcerer Posts: 24,905 Karma: 47303824 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	When a book is deleted from a Kobo device using the calibre, the following is done: - Update the database to remove appropriate rows from tables: content, content_settings, ShelfContent, ratings, Activity, shortcover_page, content_keys. - The cover images are deleted and the folder is removed if it is empty. - The book is deleted and the folder is removed if it is empty. From my tests, this is the same as when the device does the deleting except the empty folders are not removed.

08-04-2014, 06:35 AM	#19
Lucas Malor Pain in the arse Posts: 758 Karma: 77856 Join Date: Apr 2013 Device: Kobo Aura One, Kindle 4	It's strange that I had no modification in the Activity table. Anyway, the folder removal is not a problem, since I removed it manually and nothing happened. I think I have to wait until I have to remove something with Calibre

08-04-2014, 07:31 AM	#20
davidfor Grand Sorcerer Posts: 24,905 Karma: 47303824 Join Date: Jul 2011 Location: Sydney, Australia Device: Kobo:Touch,Glo, AuraH2O, GloHD,AuraONE, ClaraHD, Libra H2O; tolinoepos	The Activity table is used for the tiles on the home screen. If the book hasn't been opened, it is likely that there is no Activity row for the book.

08-06-2014, 08:18 AM	#21
Lucas Malor Pain in the arse Posts: 758 Karma: 77856 Join Date: Apr 2013 Device: Kobo Aura One, Kindle 4	Ok, it rehappened. This time I've not removed books, but added some of them. After reboot, some books had broken tiles and new books were missing. I've done a soft reset and tried to reproduce the problem, with calibre in debug mode this time. Nothing happened. It seems the issue is not reproducible, so I'll always start calibre in debug mode from now, logging the output.

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