On 08.02.2011 16:34, Bert Huijben wrote: > An even better solution would be that SQLite tries to do things completely in > memory and only *creates* a tempfile when needed. (It seems it now creates > the file anyway; but doesn't use it until needed. Introducing a heavy > performance penalty on NTFS, but not on extXfs)
You mentioned testing on journalled filesystems. Maybe you don't consider ext3 and ext4 to be journalled, but my tests were done on journalled HFS+ on Mac OS. Yes, creating a temporary file is moderately expensive. But in the approach I showed, you really only create one temporary table and/or database per WC operation, not 50 zillion. That said, I agree that a lot more testing and measuring needs to be done. And after all, a memory-backed temporary table is in the worst case backed by swap space. -- Brane
