Predicting ION_Data database growth for devices integrated using the Modbus Device Importer

Tìm các câu hỏi thường gặp

For devices integrated into ION Enterprise via the MDI(Modbus Device Importer), there is rough method to estimate the space required to log data into the database if data logging has been configured in the devices MDI template.
WARNING - the accuracy of this method may vary considerably.

--------------------------------------------------------------------

Add up the # bytes used by each Column's data type in the ION_Data.dbo.Datalog table:

DataLogStampID = int = 4 bytes

Value = float = 8 bytes

QuantityID = smallint = 2 bytes

==========================

Total = 14 bytes / DataLog record

http://msdn.microsoft.com/en-us/library/ms187745.aspx

http://msdn.microsoft.com/en-us/library/ms173773.aspx

In addition, you also have a corresponding DataLogStamp record for each data interval for each meter.

1 DataLogStamp record = int, int, datetime, datetime, real = 4 + 4 + 8 + 8 + 4 = 28 bytes

For a an example:

1 device, recording 50 data points each @ 15-minute intervals.

Then for 1 day(96 intervals):

96 intervals x 1 meter x 50 datapoints = 4800 DataLog records

4800 DataLog records *14 bytes each = 67200 bytes

96 intervals x 1 meter = 96 DataLogStamp records

96 DataLogStamp records * 28 bytes each = 2688 bytes

==================

69888 bytes total

69888 bytes / 1024 bytes/kB = 68.25kB per day per device

Events and Waveforms generated by PQ events are not possible to predict as many may occur in a given time frame.

---------------------------------------------------------------

In the real world database file growth is dictated by a number of other considerations including the Autogrow settings of the database and Container Size settings, and whether the physical drive is IDE or SCSI or RAID etc.

The best way to predict database growth is to take regular readings from the system in question, and extrapolate from past growth statistics.

Legacy KB System (APS) Data: RESL200983 V1.0, Originally authored by DaMi on 01/09/2010, Last Edited by DaMi on 01/09/2010
Related ranges: ION Enterprise V5.6, ION Enterprise V6.0