[iOS4] CMDeviceMotion and timestamp problem

Question

Hi,
Excuse my English as it isn't my primary language.
I hava a problem using an instance of CMDeviceMotion. I need data from both the gyro and accelerometer and the frequency of sample is set at the maximum, 100.
I also need the timestamp at which the sample was taken. However, at the beginning the timestamp doesn't change even if the acceleration and gyro change. I got something like that :
0.003779 -0.050910 0.001185 933.604339
0.035029 -0.042457 0.019893 933.604339
0.062266 -0.009147 0.084819 933.604339
0.069300 0.012292 0.092631 933.604339
0.047862 0.018517 0.091456 933.604339
0.035304 0.029885 0.084575 933.604339
0.032496 0.039498 0.083583 933.604339
We have acceleration.x, .y, .z and the timestamp. As you can see the timestamp doesn't change for about 60 upgrades ~6 seconds.
Besides, when it finally starts upgrading, it sometimes sample twice the accelreation/gyro at the same timestamp :
0.115215 0.005342 -0.051157 1385.964002
*0.120561 0.019797 -0.054112 1385.977830*
*0.122637 0.031470 -0.051182 1385.977830*
0.113840 0.042271 -0.045493 1385.992829
Here is my code :
In the viewDidLoad method :
motionManager = [[CMMotionManager alloc] init];
motionManager.deviceMotionUpdateInterval = 0.01;
frequence = 100;
Then I have a method invoked by a button :
[motionManager startDeviceMotionUpdatesToQueue:[NSOperationQueue currentQueue]
withHandler: ^(CMDeviceMotion *motionData, NSError *error)
CMRotationRate rotation = motionData.rotationRate;
CMAcceleration acceleration = motionData.userAcceleration;
NSLog(@"rotation rate = [%f, %f, %f, %f]", rotation.x, rotation.y, rotation.z, motionData.timestamp);
NSLog(@"acceleration rate = [%f, %f, %f, %f]", acceleration.x, acceleration.y, acceleration.z, motionData.timestamp);
Any help appreciated,
Thanks for your time
Loïs

Answer 1

Oracle FAQ page: http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-faq-090281.html#08_01
Well obviously that was really stupid.
I'm adding some queries to an older part of our code base and while reading through the documentation for one of the classes I found that we weren't using our normal Hibernate queries because we needed to ensure that we weren't sending Timestamps to Oracle. Apparently the Timestamp would be converted to a Date because the column in the database was of type DATE. This was causing problems because the DATE column's index was being ignored and the table contains millions of records.
Not sure I follow that logic.
If the value was going into the database then it would update the index.
From that only one of the following could be true.
1. It wasn't going into the database.
2. It was being truncated to a date.
The Oracle FAQ seems to indicate that this has been fixed in the 11.1 JDBC drivers. I know that I can use 11.1 JDBC drivers with a 10.2.0 database, but will it use the new 11.1 mappings for DATE and TIMESTAMP or the old 10.2.0 mappings? I would agree with your interpretation of the FAQ.
And I would then follow it up by testing both with the old driver and the new.