Delta Collapse Rows
Enables row collapsing in Persistent Staging Area (PSA) Processing by retaining the first row of sequences with identical values and differing timestamps, discarding subsequent duplicates to enhance storage efficiency.
The collapse is implemented as a ROW_NUMBER() selection partitioned by the primary key and ordered by the effective date: within a sequence of rows with identical values, only the first row is kept. Collapsing applies to persistent loads from staged files; it is bypassed for CDC sources, when distinct row selection is used, when the delta is already derived, or when all rows are staged.
When to Change This Setting
Keep the default Y so repeated deliveries of unchanged data do not accumulate as duplicate versions in the PSA. Disable it to persist every delivered row version, including consecutive identical ones.
Related Settings
| Setting | Interaction |
|---|---|
| Delta Stage All Rows | Disables collapsing when enabled |
| Delta Is Derived | Disables collapsing when enabled |
| Select Stage Row Distinct | Replaces the row-number selection collapsing builds on |
| Select Blob Row Order By | The order direction of the row-number selection |
Notes
- This setting is part of the Staging Persistent settings category.
- The default value for this setting is
Y.