I'm trying to write some defensive code that is able to recover from 
database corruption. The idea is that if a disk fails and a database 
becomes corrupt it can be detected and synchronised from a backup copy.

To this end, I've just been trying to write a function that returns true 
only when it is sure the database is ok. I use PRAGMA integrity check; and 
compare the returned string with "ok". When I tried this with a few random 
database changes, though, I had a hard time trying to get the corruption 
to trigger. I did the following:

CREATE TABLE foo(bar);

I then went in with a text editor and started modifying the bar record. I 
changed "bar" to "car", but the change was not detected. I started 
modifying characters to the left and right of the "car" string, but still 
no corruption. I was able to get corruption to be detected when I 
truncated the file.

Can I take it from this behaviour that there isn't any checksum checking 
going on apart from headers and the BTrees themselves? Will the 
integrity_check at least guarantee me that I won't at some later stage get 


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