overwrite filter strategy

[stankiewicz]

Goal - Bring more flexibility/strategies into incremental models. updatePartitionFilter is not enough.
Additional insert-overwrite strategy with DML (delete) before model execution. Delete statement should select partitions dynamically or based on static input.

Why it's needed:
Customers are calculating expensive aggregates. Sometimes there are no unique keys in input and output - incremental model is append only and leveraging pre-statement is error prone.

Solution suggested:
Adapter for incremental tables should support:

• Append only (especially if no keys are provided)
• Merge statement if keys are provided
• Insert overwrite via delete from and insert

Partitioning should not be enforced, some SCD tables, like in data vault can be clustered only.

Insert overwrite strategy allows setting a overwrite_filter:

• Default (empty) - when partition_by is used, then there will be DML invoked that is running DELETE from based on columns used with partition_by, otherwise it will fail
• Custom like overwrite_filter = "current_date()" or overwrite_filter=${dataform.projectConfig.vars.date}