TDMS

[B3guy]

I just learned about TDMS files at NIweek 2011, but I haven't played with it yet.  How does the speed of querying/updating TDMS files compare to using Access?

[odessy27]

TDMS is capable of logging very high speed data. I never played with Access. TDMS is good for storing huge amounts of data with great speeds, also ease of use and creating header for a data file is one of the great advantages over other file formats. You can also refer to this article that compares TDMS with other formats.

[YongqingYe]

TDMS is specially designed for high speed streaming use case. Together with LabVIEW 2011, NI PXIe-1075 Chassis and 4 NI HDD-8265 RAID Array, the performance of data streaming should be around 3 GB/s. I'm prettey sure that regarding performance of data streaming, TDMS can beat Access easily. Access or other popular database is designed for structual SQL query.

[B3guy]

I'm looking at using TDMS as a potential high speed solution instead of using SQL, so I'm more interested in the equivalent "SELECT" and "UPDATE" functions in TDMS.  For example, can you update results similar to UPDATE queries? 

[Ben]

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@YongqingYe wrote:

TDMS is specially designed for high speed streaming use case. Together with LabVIEW 2011, NI PXIe-1075 Chassis and 4 NI HDD-8265 RAID Array, the performance of data streaming should be around 3 GB/s. I'm prettey sure that regarding performance of data streaming, TDMS can beat Access easily. Access or other popular database is designed for structual SQL query.

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There should be a big asterisk next to that statement regarding the hardware required. With many PC running off a PCI bus (limited to 130 MHz) numbers like those are hardly acheivable.

Please share the hardware config required to get that type of performance.

RE: Updates

No can do in TDMS.

Ben 

[Julianne_K · Accepted solution]

Hello, 

The TDMS file format does not operate the same way as the SQL does. That is, it does not use "queries" to access the data, but instead uses functions to read and write the data. The TDMS file format is beneficial for attaching descriptive information to the measurements while streaming data to disk. For more information about using the TDMS data type for writing data, you can see these links:

http://zone.ni.com/devzone/cda/tut/p/id/11943

http://zone.ni.com/devzone/cda/tut/p/id/9334

Also, the speed which you can obtain data depends on the hardware that you have. You may want to contact the National Instruments Sales team to see if you need additional hardware for your high speed application. You can contact us at (888) 280-7645.