pierr wrote: > > > 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.) > >
I was wrong here. In my application (Not the test enviroment mentiond above), after the sqlite eating up more than 8M bytes in the memory , I dumpded the database to the Flash but it is only 360K which is very reasonable for my application. The database was configured as cache_szie = 20 ,page_size=1024 ,so the page cache would not take too much memory ,it should be less than 100K according to above measurement. So, for the non-memory based data base ,the total storage needed is : generated database size + memory used by sqlite3 internal. But for the memory database, the total storage needed will be much bigger than that. What will eat the extra buck of memory here? I can think of the journey file ,but it should be K level memory.. Thanks for help me out. -- View this message in context: http://www.nabble.com/How-to-how-many-memory-is-used-by-sqlite-tp24034261p24073060.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
