> What is the "page size"? Aren't sqlite dbs portable to any > platform/processor? Could it be that sqlite installed on my 64-bit machine is > writing a 64-bit db, but our app and the sqlite3 lib is only 32-bit? Seems > like any good file format wouldn't care about that and knows how to > read/write the same no matter what.
You understand correctly that SQLite database is portable and doesn't depend on platform bitness or anything like that. Page size is (to explain it roughly) size of elementary data block in the database file. You can see this size using "pragma page_size" (see http://www.sqlite.org/pragma.html#pragma_page_size). At the time of database creation you can change page size using the same pragma statement. And I believe the only time when page size matters (besides some performance considerations) is in this backup API your app uses. So to fix your problem you need to issue a correct "pragma page_size=..." statement at the time of creation of the database (probably in-memory one). Pavel On Mon, Nov 7, 2011 at 10:59 AM, Mills, Steve <smi...@makemusic.com> wrote: > I've inherited some python and sqlite work and am trying to figure it out. > I've done neither before, so be kind. > > There are some python scripts that generate a sqlite db, then our app has > uses sqlite3 code library to read that db and copy it to a memory-based db (I > assume so we can make changes to it and perhaps write it out to a different > file, or at least prevent the source db from being changed). When I do the > copy (which calls sqlite3_backup_step(dest, -1)), it returns 8 > (SQLITE_READONLY). > > I see some documentation in sqlite3.h that says it might return > SQLITE_READONLY if "The destination database is an in-memory database and the > destination and source page sizes differ." > > What is the "page size"? Aren't sqlite dbs portable to any > platform/processor? Could it be that sqlite installed on my 64-bit machine is > writing a 64-bit db, but our app and the sqlite3 lib is only 32-bit? Seems > like any good file format wouldn't care about that and knows how to > read/write the same no matter what. > > Any help would be greatly appreciated. Thanks! > > -- > Steve Mills > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
