hi,
i am evaluating sqlite performance for mobile platform now.
i found something discussable about memory footprint and leakage.
the highest water line of memeory usage is 44611bytes (by malloc() ), and
there seems a large memory leakage (34017bytes) in my testing scenario.
'cache_size' is set to the smallest, '1', but i dont know why it still use
so much. for low-profile mobile platforms, such amount seems too much.
can somebody tell me something about this?
-----the way i measure the memroy usage----
in os_common.h
sqlite3GenericMalloc(int n){
char *p = (char *)malloc(n+8);
...
...
if( p ){
*(int *)p = n;
}
currentMemoryConsumption += n;
if (currentMemoryConsumption > maxMemoryConsuption)
{
maxMemoryConsuption = currentMemoryConsumption;
}
return (void *)p;
}
void sqlite3GenericFree(void *p){
assert(p);
currentMemoryConsumption -= *((int*) ((char*)p - 8));
...
...
}
--------------------------testing
scenario--------------------------------------
the testing is done with windows filesystem,
cache_size=1; page_size = 1k (default),
the database being operated on contains 250 enties, no index:
contacts.db size: 7,168 bytes
CREATE TABLE contacts (name text,phone int);
A.H.|1439
Abel|1654
Absalonsgade,|1658
...
...
the queries are:
select number from contacts where rowid = 1
select number from contacts where rowid = 125
select number from contacts where rowid = 64
INSERT INTO contacts values('kim','0000')
INSERT INTO contacts values('wang','0000')
update contacts set phone='34' where name = 'kim'
update contacts set phone='71' where name = 'wang'
update contacts set phone='0000' where name = 'Eskildsgade,'
update contacts set phone='0000' where name = 'Bustrupgade,'
begin
INSERT INTO contacts VALUES('abc','49')
INSERT INTO contacts VALUES('klaus','41')
update contacts set phone='1657' where name = 'Eskildsgade,'
update contacts set phone='1737' where name = 'Bustrupgade,'
delete from contacts where name = 'abc'
delete from contacts where name = 'klaus'
commit
delete from contacts where name = 'kim'
delete from contacts WHERE name = 'wang'
delete from contacts where name = 'Eskildsgade,'
delete from contacts WHERE name = 'Bustrupgade,'
