What is TRACK HISTORY? · Ultra Transcenders glossary

Decides which columns count towards SCD Type 2 versioning in AUTO CDC. Changes to any other column just overwrite the current row.

Also called track_history_column_list.

In the Ultra Transcenders books

Each book explains TRACK HISTORY in context, with comparison tables and the common traps.

COUNT
A DAX function returning how many non-blank numbers, dates or text values a column contains. Boolean columns need COUNTA instead, and for counting the rows of a table COUNTROWS is the better choice.
History tracking
Retains previous versions of a row instead of replacing them. Lakeflow Connect tables leave it off by default, and in AUTO CDC the TRACK HISTORY option restricts which columns create new versions.
Versioning
When enabled on Blob Storage, earlier versions of each blob are retained. Point-in-time restore depends on it, though it never purges data itself.
AUTO CDC
The Lakeflow pipelines API for change data capture: it merges incoming changes into a streaming table, keeping either just the latest values (SCD 1) or full history (SCD 2), and uses an ordering column to cope with records that arrive late. A snapshot variant also exists.

SCD
Slowly changing dimension. Type 1 keeps only current attribute values; type 2 retains every past version, bounded by __START_AT and __END_AT. Pipelines get both via AUTO CDC (STORED AS SCD TYPE 1 or STORED AS SCD TYPE 2), while TRACK HISTORY ON names which columns produce history.