A FILTER function is used instead of modifying the filter context

The FILTER function is used instead of modifying the filter context.

Remarks

The FILTER function can be expensive from a materialization standpoint. When the filter condition only references physical columns of the iterated table, then it is possible to filter the table through the filter context by using CALCULATETABLE.

Example 1

Transform FILTER/RELATEDTABLE in CALCULATETABLE. Remove FILTER and RELATEDTABLE, replacing them with CALCULATETABLE. Use KEEPFILTERS over the predicate to preserve the same semantics.

Original code

FILTER (
    RELATEDTABLE ( Sales ),
    Sales[Quantity] > 1
)

Possible optimization

CALCULATETABLE (
    Sales,
    KEEPFILTERS ( Sales[Quantity] > 1 )
)