On Apr 21, 2010, at 4:37 PM, Pavel Ivanov wrote: > I don't know anything about internal support of pages bigger than 32k. > But I want to warn you: each table and each index in SQLite occupy at > least 1 database page. So let's say you have 4 tables with 1 > additional index each (besides 'integer primary key' one). With 256k > pages this schema will result in a database of more than 2 Mb without > any data stored. Is your embedded FS okay with this storage amount?
Furthermore, SQLite changes whole pages at a time. So in a database with 256kB pages, if you change a single byte, you still have to write 256kB both to the rollback journal and to the database file. > > > Pavel > > On Tue, Apr 20, 2010 at 4:51 PM, Tom Broadbent > <tom.broadb...@plasticlogic.com> wrote: >> i've read in the docs that SQLITE_MAX_PAGE_SIZE can't be > 32k >> (below). is this limitation still valid? >> >> we have an embedded FS that is _very_ slow and performs best w/ a >> write page size of 256k. will bad things happen if i configure >> SQLite w/ 256k pages? >> >> thanks >> tom >> >> Maximum Database Page Size >> >> An SQLite database file is organized as pages. The size of each >> page is a power of 2 between 512 and SQLITE_MAX_PAGE_SIZE. The >> default value for SQLITE_MAX_PAGE_SIZE is 32768. The current >> implementation will not support a larger value. >> >> It used to be the case that SQLite would allocate some stack >> structures whose size was proportional to the maximum page size. >> For this reason, SQLite would sometimes be compiled with a smaller >> maximum page size on embedded devices with limited stack memory. >> But more recent versions of SQLite put these large structures on >> the heap, not on the stack, so reducing the maximum page size is no >> longer necessary on embedded devices. There is no longer any real >> reason to lower the maximum page size. >> >> ______________________________________________________________________ >> This email has been scanned by the MessageLabs Email Security System. >> For more information please visit http://www.messagelabs.com/email >> ______________________________________________________________________ >> _______________________________________________ >> 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 D. Richard Hipp d...@hwaci.com _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
