Update semantic model or Dataflow efficiently

Power BI incremental refresh is partition-based, so it can refresh partitions efficiently, but it does not “update individual rows” inside an already-loaded partition.

Use:

• RangeStart/RangeEnd on a DateTime column (must fold) 

• optionally Detect data changes using a separate “LastModifiedDateTime” column so only affected partitions refresh

But remember, updates are handled by refreshing the whole partition, not row-by-row upserts.

The duplicate value problem probaly happens because of Range Start/End parameters wrong usage. Example filtering should be like below:

= Table.SelectRows(
    Source,
    each [LastModifiedDateTime] >= RangeStart
     and [LastModifiedDateTime] <  RangeEnd
)