Soterre PBI Analyzer

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Auto Date Tables Identified ​

Detects models using Power BI's automatic date/time feature, which generates hidden date tables that can bloat the model.

What It Detects ​

This flag identifies the hidden date tables that Power BI's "Auto date/time" feature generates. Power BI creates one such table (named LocalDateTable_<guid>) behind every date/datetime column when the feature is enabled. The analyzer surfaces these hidden tables so you can decide whether to disable "Auto date/time" in Power BI Options > Data Load and replace them with a dedicated date dimension.

Why It Matters ​

  • Model bloat — Each date/datetime column gets its own hidden calendar table. A model with 10 date columns will have 10 hidden date tables, each with a full year-level hierarchy.
  • Increased memory usage — Auto date tables span the full range of values in the column, often generating rows for years that are irrelevant to the analysis.
  • Slower refresh times — More tables in the model means more processing during data refresh.
  • Redundant with custom date tables — If the model already has a dedicated date/calendar dimension table, the auto-generated tables are completely redundant.

Trigger Conditions ​

A table is flagged when:

  1. Its name matches the pattern LocalDateTable_* — Power BI's auto-generated hidden date tables.
  2. The model contains a relationship connecting that hidden table to a user table (the analyzer checks both directions). This relationship is used to recover the source table and its date column; a LocalDateTable_* with no such relationship is skipped.

The analyzer does not inspect column data types and does not read any "Auto date/time enabled" setting or annotation. It infers the feature purely from the presence of these hidden tables and their relationships.

Note: This flag detects the presence of auto date tables, not a threshold count.

Output ​

Per detected auto date table the flag records:

FieldDescription
nameThe hidden auto-generated table (e.g. LocalDateTable_<guid>)
autoDateInfo.sourceTableThe user table whose date column the hidden table was generated for
autoDateInfo.sourceColumnThe date/datetime column the hidden table hangs off (recovered from the relationship)

Note: In the UI this appears only as an Auto Date badge on the table's row in the tables list. No date range is computed, and there is no workspace or report field on this flag's output.

Notes and Edge Cases ​

  • Global setting — The "Auto date/time" feature is a global Power BI Desktop setting (File → Options → Data Load). Disabling it affects all new columns but does not retroactively remove existing auto tables from saved .pbix files.
  • Custom date tables — If the model already includes a proper date dimension table, disabling auto date/time is strongly recommended to avoid duplication.
  • Relationship required — A LocalDateTable_* is only reported when a relationship links it to a real table. This is how the analyzer recovers the source table and column; a hidden table with no relationship is silently skipped.
  • Wide date ranges — In Power BI, columns with erroneous dates (e.g., 1900-01-01 default values) can cause auto date tables to span over 100 years, significantly inflating model size. The analyzer flags the presence of the hidden table but does not measure this range itself.