D. Richard Hipp wrote: > > > On Jun 15, 2009, at 9:04 AM, pierr wrote: > >> >> Hi all, >> I am using an memory type sqlite database in our embedded >> application. After the applicate run a while ,the system will run >> ourt of >> out of memory. So, is there a way to know how many memory is used by >> sqlite? >> That would include the memory for page cache , any other other >> internal >> memory used the sqlite ,as well as the memory for database itself. >> Thanks >> for your help. > > http://www.sqlite.org/c3ref/memory_highwater.html > http://www.sqlite.org/malloc.html > >
By using the memory_highwater api above , I found that most of the memory is used for page cache. By limiting the cache size , I can have a good control of how many heap memory will be used. INSERT Record Numbers PAGE SiZE CACHE SIZE HIGH WATER MARK (110bytes per record) 1000 1024 20 98,256 1000 1024 2000 271,040 8000 1024 2000 1,562,144 8000 1024 20 99,200 And as Simon suggest ,when I close the connection, the memory used by sqlite will be Zero. I am more clear about how sqlite use memory now , however ,as I am using memory database ,I also cares about the database size. That is what is proportion of database size to the raw data size. I insert a record of 112 bytes 10,1000,and 10000 times repectively and here list the output database size. For The last case ,it has a propotion about 1.45. What cost the extra 0.45 here beside the btree? 10240 2009-06-17 14:38 /etc/eit.flash.sqlite.10 171008 2009-06-17 14:32 /etc/eit.flash.sqlite.1000 1634304 2009-06-17 14:42 /etc/eit.flash.sqlite.10000 (I am using the Flash database instead of the memory data here as I think the result should be the same.) Here are the table structure. For the 112 bytes in each record , 100 bytes goes to the event_name field. CREATE TABLE IF NOT EXISTS tblEvent_basic( sguid INT, service_id INT, event_id INT, start_time VARCHAR(5), duration VARCHAR(3), running_status INT, free_ca_mode INT, event_name VARCHAR(256), text VARCHAR(256)) Thanks for your comment. -- View this message in context: http://www.nabble.com/How-to-how-many-memory-is-used-by-sqlite-tp24034261p24068533.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
