Following is LINQ code to query Windows Azure “WADLogsTable” in which you can get rows which are stored after a specific DateTime.


public static CloudTableQuery<TEntity> GetDiagnosticEntities<TEntity>(
this TableServiceContext tsc, String tableName,
DateTime startTime, DateTime endTime,
String deploymentId = null, String roleName = null,
String roleInstanceId = null) where TEntity : WadTableEntity {

const String TickFormat = "D19"; // 19-digit, 0-padded
String startTimeStr = startTime.Ticks.ToString(TickFormat);
String endTimeStr = endTime.Ticks.ToString(TickFormat);

String startRoleInstance = AzureDiagnosticsRowKey(deploymentId, roleName, roleInstanceId);
String endRoleInstance = startRoleInstance.GetNextKey();
tsc.MergeOptions = MergeOptions.NoTracking;
return (from e in tsc.CreateQuery<TEntity>(tableName)
where (e.PartitionKey.CompareTo(startTimeStr) >= 0
&& e.PartitionKey.CompareTo(endTimeStr) < 0)
&& (e.RowKey.CompareTo(startRoleInstance) >= 0
&& e.RowKey.CompareTo(endRoleInstance) < 0)
select e).AsTableServiceQuery();
}

private static String AzureDiagnosticsRowKey(String deploymentId = null, String roleName = null, String roleInstanceId = null) {
var sb = new StringBuilder();
if (!String.IsNullOrWhiteSpace(deployment)) {
sb.Append(deployment).Append("___");
if (!String.IsNullOrWhiteSpace(role)) {
sb.Append(role).Append("___");
if (!String.IsNullOrWhiteSpace(roleInstance))
sb.Append(roleInstance);
}
}
return sb.ToString();
}

private static String GetNextKey(String @string) {
var sb = new StringBuilder(@string);
sb[sb.Length - 1]++;
return sb.ToString();
}

Note: If you will not use tsc.MergeOptions = MergeOption.NoTracking, the more Iogs entries you scan, your application will consume more and more memory.