The NTFS cluster size is usually 4K, unless you have changed it (you can use fsutil or chkdsk to see what the cluster size is). Windows does I/O in units of a cluster. Therefore the smallest (and largest) I/O which Windows will do is 1 Cluster, or 4K. While you may set the page size larger or smaller at the application level, Windows will always do I/O in cluster units. So if you set the page size to 1K, it will still I/O 4K for each page read/write, and if you set it larger than the cluster size, then it will scatter-gather the number of clusters required to fill your request.
> -----Original Message----- > From: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users- > bounces at mailinglists.sqlite.org] On Behalf Of Olivier Mascia > Sent: Monday, 29 February, 2016 02:15 > To: SQLite mailing list > Subject: Re: [sqlite] Page_size > > > > Le 29 f?vr. 2016 ? 09:22, Jim Wang <2004wqg2008 at 163.com> a ?crit : > > > > hi,all > > > > Could different page_size do impact on the speed of retrieving > record? > > Is page_size 8192 faster than page_size 1024 or page_szie 4096? or > The pagesize has nothing to do with the retrieving speed. > > > > Best reagard! > > Jim Wang. > > I'm eager to read the comments of seasoned users on this. > > On my side, having started using SQLite very recently (December 2015), > after a lot of tests using real data, we have found the sweet spot (for > us, and for now) to be 4K page sizes, which just happen to be the virtual > memory page size of Windows system (except older Itanium versions). > Though we use a slightly smaller cache size (between 500 and max 1000 > pages) instead of the default 2000 pages. We use private caches per > connection only, and use only wal mode. > > You'll obviously pack more record and index cells per page when the page > size is larger, but you will have larger I/O too to read or write any of > those pages. Your cache memory usage will obviously be higher with larger > page size, unless you cache fewer pages (which we chose to do). > > I can't bring any comment regarding other OS. > But there is probably not ONE answer to your question. > > -- > Meilleures salutations, Met vriendelijke groeten, Best Regards, > Olivier Mascia, integral.be/om
