Re: [sqlite] How to retrieve number of cached pages in memory?
> See the "Pager" data structure and associated variables and functions > in "sqlite-3.5.x/src/pager.c". OK, it seems that the number I am interested in is stored as part of the Pager struct: int nPage; /* Total number of in-memory pages */ Now I just have to figure out how to access this number reliably. Many thanks, Ralf ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] How to retrieve number of cached pages in memory?
You're right! A grep of the source code confirms that. My mistake. - Richard Jay A. Kreibich wrote: > On Tue, Apr 22, 2008 at 03:33:27PM -0700, Richard Klein scratched on the wall: >> You can call sqlite3_memory_highwater() to find >> the maximum amount of memory (in bytes) that your >> app has used. >> >> Then you can divide this number by 2000 (the default >> size of a page) to determine the max number of pages >> that have been cached. > > > The default page size is 1024 bytes. > > The default cache size (in pages) is 2000. > > > (At least according to http://www.sqlite.org/compile.html) > > > -j > ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] How to retrieve number of cached pages in memory?
On Tue, Apr 22, 2008 at 03:33:27PM -0700, Richard Klein scratched on the wall: > You can call sqlite3_memory_highwater() to find > the maximum amount of memory (in bytes) that your > app has used. > > Then you can divide this number by 2000 (the default > size of a page) to determine the max number of pages > that have been cached. The default page size is 1024 bytes. The default cache size (in pages) is 2000. (At least according to http://www.sqlite.org/compile.html) -j -- Jay A. Kreibich < J A Y @ K R E I B I.C H > "'People who live in bamboo houses should not throw pandas.' Jesus said that." - "The Ninja", www.AskANinja.com, "Special Delivery 10: Pop!Tech 2006" ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] How to retrieve number of cached pages in memory?
On Wed, Apr 23, 2008 at 12:19:45AM +0200, Ralf Junker scratched on the wall: > I need to retrieve the number of pages a SQLite database connection has > currently allocated in memory. The documentation unfortunately turned up > no results. I know about "PRAGMA cache_size", but this returns the > maximum number of pages possibly allowed in the cache, not the actual > number of pages currently cached. > > My aim is to calculate the accurate number of bytes actually consumed by > a single cached page. This figure will then allow to set PRAGMA > cache_size to a more precise value in order to limit memory usage. > > I do mind using undocumented APIs and will not cry tears if they > change without notice, so any pointers are welcome! See the "Pager" data structure and associated variables and functions in "sqlite-3.5.x/src/pager.c". -j -- Jay A. Kreibich < J A Y @ K R E I B I.C H > "'People who live in bamboo houses should not throw pandas.' Jesus said that." - "The Ninja", www.AskANinja.com, "Special Delivery 10: Pop!Tech 2006" ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] How to retrieve number of cached pages in memory?
You can call sqlite3_memory_highwater() to find the maximum amount of memory (in bytes) that your app has used. Then you can divide this number by 2000 (the default size of a page) to determine the max number of pages that have been cached. - Richard Klein Ralf Junker wrote: > I need to retrieve the number of pages a SQLite database connection has > currently allocated in memory. The documentation unfortunately turned up no > results. I know about "PRAGMA cache_size", but this returns the maximum > number of pages possibly allowed in the cache, not the actual number of pages > currently cached. > > My aim is to calculate the accurate number of bytes actually consumed by a > single cached page. This figure will then allow to set PRAGMA cache_size to a > more precise value in order to limit memory usage. > > I do mind using undocumented APIs and will not cry tears if they change > without notice, so any pointers are welcome! > > Many thanks, > > Ralf > > ___ > 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
