On 09/05/2011 10:47 PM, Rado Rado wrote:
I'm running simple prepared SELECT statement in loop ( about 3000 times ).
It is something like "SELECT value FROM t WHERE t_id=? AND name=?". For most
calls the row does not exist, step() returns SQLITE_DONE so I call reset
after that(). The loop takes about 0.25 second and result seems to be
correct.
When I execute any SELECT query (using different table, like SELECT * FROM
t2) which returns some row and I won't call reset() so it stays open, when I
execute the loop described above after this, it is much faster (0.08 sec.).
Is it because of some lock obtained for my process by opened statement? Or
am i doing something wrong?
It will be the overhead of obtaining a read lock. In the first case,
you are obtaining and releasing a database read lock (a system call)
3000 times. In the second case, you are only doing it once.
You could get the same effect by wrapping your loop in a BEGIN/COMMIT
block.
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