Forum Discussion
Dataflow and Delta Tables - strange behaviour
Replace = basically deletes all the records in the table and replaces the content in the table with new one
Append = Simply adds new records to an existing table
A method such as "UPDATE AND INSERT" would probably update existing records if it finds any and will try to also insert new ones if they dont already exist. This method doesn't exist today, but you can create a new idea on aka.ms/FabricIdeas for it.
So, in Fabric, does the "Replace" method when setting a Data Destination in a Gen 2 Dataflow replace the whole table, or just the records that have changed?
It happened again. In a Query, I added a step to filter out the 0's.
But after a few refreshes, the Delta Table still held those 0's!
I had to delete the Delta Table completely from the Lakehouse to get this working properly.
Is this expected behaviour, or a bug?
Replace = basically deletes all the records in the table and replaces the content in the table with new one
Append = Simply adds new records to an existing table
A method such as "UPDATE AND INSERT" would probably update existing records if it finds any and will try to also insert new ones if they dont already exist. This method doesn't exist today, but you can create a new idea on aka.ms/FabricIdeas for it.
- Thanks for explaining this. I appreciate Fabric is still in Beta and Preview, but I often still get buggy behaviour with this, where Replace doesn't always replace the whole table afresh. Cheers,