Re: [sqlite] Two different DLLs linked statically to Sqlite and loaded in the same process

[Vitali Lovich]

 From what I remember, an attempt at database compatibility is attempted 
across major revision numbers (i.e. all SQLite v2 revisions can read 
SQLite v2 databases, all SQLite v3 revisions can read SQLite v3 
databases), but I can't remember.  I don't believe it's generally 
recommended to be doing what you are doing - is there any reason why 
they both can't be dynamically linked against a sqlite DLL, and then 
supply only the one version?

A good way to test would be to grab the versions being used by the DLLs 
off of the website, and write your own little test harness that 
simulates the situation and try to use 1 DLL version to write the 
database, and another to read  modify it, and finally read it back 
using the 2nd.

If you open a database read-only, then no corruption should occur since 
SQLite will not have the permissions on the file handle.

Kalipto wrote:
 Hello,

 For some particular reasons, one process loads two different DLLs, each 
 one linked with a static library of Sqlite. This two DLLs access the 
 same database. I know that there is no problem if you access to the 
 database from 2 different processes. But I was wondering if there would 
 be a problem in this situation. Maybe the two libraries would improperly 
 share some objects like mutex in the same process environment ?

 Another question is, does it makes a problem that the 2 versions of the 
 static Sqlite libraries are different (not the same release number) ?

 I ask all these questions because sometimes (even if it is rare) the 
 database gets corrupted. So I was wondering if it could be an 
 explanation of this problem or if I must look into another direction 
 (maybe the program would badly write in the database structure and 
 corrupt it).

 Last question: if I open a database in read-only mode, does it guarantee 
 that the database will not be corrupted.

 Thanks for your answers.

 Kal
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[sqlite] Two different DLLs linked statically to Sqlite and loaded in the same process

[Kalipto]

Hello,

For some particular reasons, one process loads two different DLLs, each 
one linked with a static library of Sqlite. This two DLLs access the 
same database. I know that there is no problem if you access to the 
database from 2 different processes. But I was wondering if there would 
be a problem in this situation. Maybe the two libraries would improperly 
share some objects like mutex in the same process environment ?

Another question is, does it makes a problem that the 2 versions of the 
static Sqlite libraries are different (not the same release number) ?

I ask all these questions because sometimes (even if it is rare) the 
database gets corrupted. So I was wondering if it could be an 
explanation of this problem or if I must look into another direction 
(maybe the program would badly write in the database structure and 
corrupt it).

Last question: if I open a database in read-only mode, does it guarantee 
that the database will not be corrupted.

Thanks for your answers.

Kal
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