On 2 Sep 2010, at 4:42am, Ben Danper wrote: > On Wed, Sep 1, 2010 at 12:46 PM, Jay A. Kreibich <j...@...> wrote: >> Maybe there would be some way to pre-populate the rollback journal >> with the full contents of the original database. Then the file could >> be truncated before the copy-back procedure. That would make it >> clear to the OS that it is free to allocate whatever file blocks it >> wants, hopefully in better patterns. The copy back could also be >> done in very large chunks. > > This is a fantastic idea! Not only truncate - since you know the new size, > you could also set the size beforehand before you start copying the pages > (similar to SQLITE_FCNTL_CHUNK_SIZE). Most filesystems will try very hard to > place it contiguously.
What does SQLite actually do if you take a table with a primary key and do this on it INSERT OR REPLACE INTO myTable SELECT * FROM myTable ? I assume that at some level it realises that no writing actually needs to be done. But could you defeat that and have that statement just force a rewrite of the entire table ? Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
