Hello again, Copying the database with Explorer and accessing it via sqlite is just a contrived example that exhibits the same problem I'm having in my application. The app does make a copy of the DB, but it has app-layer locking that will prevent modifications unless someone decides to start fiddling with the DB outside of my software (in which case I have bigger problems). The app is multi-threaded, and a thread other than the copying thread may attempt to open the DB and read from it while the copy is occurring.
My contrived example aside, I just discovered that issuing the VACUUM command on the same 20 GB DB in sqlite3 causes similar memory issues, even when another process is not accessing the database file. sqlite3.exe has a peak working set of 40 MB in Task Manager, but Resource Monitor reports 99% Used Physical Memory (of 4 GB). If it were all buffer cache, I'd expect that simply copying the file would result in the same amount of memory being used, but it doesn't. I'm going to head to a Windows forum to try to find out more about what's happening, but the list users may want to be aware of this if they plan on using large sqlite DBs with Windows 2008. Thanks, -Stan On Wed, Jul 8, 2009 at 10:39 AM, Mark Spiegel<mspie...@vipmail.com> wrote: > In the meantime, you may want to look at the backup interface provided > by SQLite. This should avoid any problems with getting an inconsistent > snapshot which you just can't avoid with explorer even if you solve the > RAM issue. You could write a command line program that just performs a > copy on a database in short order to use in place of explorer. Someone > here could probably post pseudo code for that in just a few minutes. > Maybe this presents its own set of problems, I don't know. > _______________________________________________ > 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
