I have heard that prepared statements with SQLite should improve performance. I wrote some code to test that, and did not see any difference in performance with using them. So, I thought maybe my code was incorrect. Please let me know if you see any errors in how I'm doing this...
[self testPrep:NO dbConn:dbConn];
[self testPrep:YES dbConn:dbConn];
reuse=0
recs=2000
2009-11-09 10:39:18 -0800
processing...
2009-11-09 10:39:32 -0800
reuse=1
recs=2000
2009-11-09 10:39:32 -0800
processing...
2009-11-09 10:39:46 -0800
-(void)testPrep:(BOOL)reuse dbConn:(sqlite3*)dbConn{
int recs = 2000;
NSString *sql;
sqlite3_stmt *stmt;
sql = @"DROP TABLE test";
sqlite3_exec(dbConn, [sql UTF8String],NULL,NULL,NULL);
sql = @"CREATE TABLE test (id INT,field1 INT, field2 INT,field3 INT,field4 INT,field5 INT,field6 INT,field7 INT,field8 INT,field9 INT,field10 INT)";
sqlite3_exec(dbConn, [sql UTF8String],NULL,NULL,NULL);
for(int i=0;i<recs;i++){
sql = @"INSERT INTO test (id,field1,field2,field3,field4,field5,field6,field7,field8,field9,field10) VALUES (%d,1,2,3,4,5,6,7,8,9,10)";
sqlite3_exec(dbConn, [sql UTF8String],NULL,NULL,NULL);
}
sql = @"BEGIN";
sqlite3_exec(dbConn, [sql UTF8String],NULL,NULL,NULL);
if (reuse){
sql = @"select * from test where field1=?1 and field2=?2 and field3=?3 and field4=?4 and field5=?5 and field6=?6 and field6=?6 and field8=?8 and field9=?9 and field10=?10 and id=?11";
sqlite3_prepare_v2(dbConn, [sql UTF8String], -1, &stmt, NULL);
}
NSLog(@"reuse=%d",reuse);
NSLog(@"recs=%d",recs);
NSDate *before = [NSDate date];
NSLog([before description]);
NSLog(@"processing...");
for(int i=0;i<recs;i++){
if (!reuse){
sql = @"select * from test where field1=?1 and field2=?2 and field3=?3 and field4=?4 and field5=?5 and field6=?6 and field6=?6 and field8=?8 and field9=?9 and field10=?10 and id=?11";
sqlite3_prepare_v2(dbConn, [sql UTF8String], -1, &stmt, NULL);
}
sqlite3_bind_int(stmt, 1, 1);
sqlite3_bind_int(stmt, 2, 2);
sqlite3_bind_int(stmt, 3, 3);
sqlite3_bind_int(stmt, 4, 4);
sqlite3_bind_int(stmt, 5, 5);
sqlite3_bind_int(stmt, 6, 6);
sqlite3_bind_int(stmt, 7, 7);
sqlite3_bind_int(stmt, 8, 8);
sqlite3_bind_int(stmt, 9, 9);
sqlite3_bind_int(stmt, 10, 10);
sqlite3_bind_int(stmt, 11, i);
while(sqlite3_step(stmt) == SQLITE_ROW) {
}
sqlite3_reset(stmt);
}
sql = @"BEGIN";
sqlite3_exec(dbConn, [sql UTF8String],NULL,NULL,NULL);
NSDate *after = [NSDate date];
NSLog([after description]);
}