Unusual huge B+ tree db file (28GB) with fatal error

[JustDancing]

I got an unusual huge B+ tree db file (28GB), tcbmgr inform shows it has fatal error. after running tcdb_dump, the file is only 20MB.

The feature of the file is following:

1) key is int64, only 15 keys

2) values are 16bytes per record, the total size wouldn't add up to 28GB.

Couldn't figure out what is the root cause since I can't reproduce this issue. Does anyone know what the problem is here?

Thanks,