I read this on Sqlite's webpage (http://www.sqlite.org/whentouse.html):
When you start a transaction in SQLite (which happens automatically before any write operation that is not within an explicit BEGIN...COMMIT) the engine has to allocate a bitmap of dirty pages in the disk file to help it manage its rollback journal. SQLite needs 256 bytes of RAM for every 1MB of database. For smaller databases, the amount of memory required is not a problem, but when database begin to grow into the multi-gigabyte range, the size of the bitmap can get quite large. If you need to store and modify more than a few dozen GB of data, you should consider using a different database engine. If I change the page size to a higher value, such as 8192, I suppose the bitmap size goes down as well.. so maybe the website text should be changed to reflect this? /Ludvig
