Question
Tata Consultancy Services
IN
Last activity: 6 Aug 2025 9:15 EDT
Using Data Set to write a BLOB value in a table
I have an external table with a PZPVSTREAM column. I am trying to write an unexposed property in the table from a data-flow using a data-set as destination. All other columns are getting saved fine with the exception of the BLOB value.
Any suggestions on this please?
Thanks
Kaisar
ai4process ltd
GB
You cannot use a Dataset to read/ write the data from Blob. Dataset always works with a flat table structure i.e. works with proeprties exposed to respective columns in DB.
You can use an Activity as a Destination and perform a save using a Savable data page to save the data. alternatively, though not recommended, you can use an Obj-Save to save the data. You can also create a Queue Processor and send the Save operation to a QP to save the data asynchronously without impacting the current Dataflow run.
Tata Consultancy Services
IN
@RaviChandra I was also of the same opinion that we cannot write blob using data-sets. But, Pega proved me wrong. We indeed can. The issue was not in the data set but, the way the blob column was being set up. Once that was corrected, the BLOB columns are getting saved as well. :)
HCA Healthcare
US
When you use a Data Set with a Data Flow to write to an external table, it can save exposed (normal) columns just fine, but it won’t populate the BLOB column (pzPVStream) because it doesn't automatically serialize the whole clipboard page like Pega does when using Obj-Save. To store data in the BLOB, you need to save the full clipboard page using standard save methods like Obj-Save inside an activity or flow. Another option is to expose the property you're trying to save so it doesn't rely on the BLOB at all. If changing your save method isn’t possible, then writing to the BLOB will likely require custom logic, which gets complex. So the best approach is to either save through a flow or expose the property in your database table.