On Tue, Nov 8, 2011 at 6:46 PM, Richard Hipp <d...@sqlite.org> wrote: > On Tue, Nov 8, 2011 at 5:50 PM, Gabor Grothendieck > <ggrothendi...@gmail.com>wrote: > >> In R, the RSQLite driver for SQLite currently has >> SQLITE_MAX_VARIABLE_NUMBER set to 999. This is used by many people >> for many different projects and on different platforms and it seems >> that a number of these projects want a larger number. Users don't >> compile this themselves so they are stuck with whatever number is >> compiled in for them. >> >> What are the considerations for setting this number? >> >> Is there any general advice that can be given on how to set this number? >> > > I just checked and it appears that MacOS Lion compiles it a 500000. > > Whenever you use a value like ?N, SQLite allocates an array of N objects, > each of 72 bytes in size. So doing "SELECT ?500000" on Lion requires a > 36MB memory allocation (with its accompanying memset()). That's really the > only downside to choosing a really large SQLITE_MAX_VARIABLE_NUMBER.
If "SELECT ?500000" allocates 500000 * 72 bytes of memory then how does that relate to SQLITE_MAX_VARIABLE_NUMBER? SQLITE_MAX_VARIABLE_NUMBER did not seem to enter the calculation at all. -- Statistics & Software Consulting GKX Group, GKX Associates Inc. tel: 1-877-GKX-GROUP email: ggrothendieck at gmail.com _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
