Why the database saved by KeePassDX have different file size compared to the PC KeePass saved?

[HaujetZhao]

Describe the bug

I am using Syncthing to sync the database between my phone and my PC, and I noticed that, every time I saved the database by KeepassDX, it's size become about 1.7MB, and every time I saved the database by PC KeePass, it's size become about 3.51MB, why would this happen?

Expected behavior Using same alogrism, I suppose they should have size after saving.

KeePass Database

• Created with: Windows KeePass 2.44
• Version: 2
• Location: local file
• Size: 3.51MB
• Contains attachment: Yes, 4 pictures and one of my Bitcoin Backup file, but all destructed, don't know why, don't know how, don't know when it happened. I'll upload one of the destructed attatchments. But now I'm afraid of putting attatchments into the database if case of data lose again.
• Destructed Picture Attatchment

KeePassDX (please complete the following information):

• Version: 2.9.18
• Build: Free
• Language: Chinese Simplified

Android (please complete the following information):

• Device: Redmi K20 Pro
• Version: 11

[J-Jamet]

There can be two explanations

1. The third-party applications you use to synchronize files do not update caches and backups are not visible. In this case, you should contact the developers of these other applications to find solutions.
2. Maybe an old bug in KeePassDX that prevents from formatting correctly the binary format of the attached files. (update your app)

Can you upload a test database to reproduce the problem? Have you tried to recover the file manually to see if KeePassDX was saving correctly with a local file manager? Because I did the tests on my side and I have no problem.

[J-Jamet]

Of course, your KeePassDX application must be up to date: 2.10.2

[J-Jamet]

I can't test your test bases without the associated passwords.

[J-Jamet]

Each time sync, Syncthing will make a copy of old file as a backup.

If this is not the expected behavior, open a ticket on the Syncthink project.

[HaujetZhao]

@J-Jamet Just wanna check it out, did this reproduced with the database I uploaded?

[J-Jamet]

No, can't reproduce. You don't indicate the entry that contains the attachments, there are many of them. Note that there is a history to your base. And for you ? the problem is reproducible since you updated the application?

[HaujetZhao]

Ah ah, forgot the history...A Lot of work then.

I'll record a video later.

[HaujetZhao]

Have this new created vault as an example, it's saved by Windows Keepass 2.44, it's size is 509KB (contains 2 attachments) test vault.zip, password is happy

But if you save it with KeepassDX, it's size will become 287KB.

[J-Jamet]

I just checked and I don't see any problem. The attached files are not altered during the save (binaries hashes remain the same) and the file formatting is repaired and ordered to take less space. https://github.com/Kunzisoft/KeePassDX/wiki/FAQ#why-is-the-database-file-smaller-after-a-save