QUESTION::Databricks delta files Spark SQL DML not supported in Fabric

Ok, but then, if this default behavior you mention is active,  why do I see NO snappy file show up in the folders, and the total number of small files is not reduced if I do not run the following commands? 

And lately, also small files is not reduced after I run the following commands from a Notebook? (the below sequence is the same cell sequence as in the Notebook):

spark.conf.set("spark.databricks.delta.optimize.maxFileSize", "10GB")
spark.conf.set("spark.databricks.delta.optimizeWrite.enabled", "true")
spark.conf.set("spark.databricks.delta.optimizeWrite.binSize", "5GB")

%%sql

OPTIMIZE RAW_SUMMARY ZORDER BY ([YEAR], [MONTH]);
OPTIMIZE RAW_TRANSACTION ZORDER BY ([YEAR], [MONTH], Direction, VehicleClass, Lane);

OPTIMIZE FACT_SUMMARY ZORDER BY ([YEAR], [MONTH], [DATE]);
OPTIMIZE FACT_TRANSACTION ZORDER BY ([YEAR], [MONTH], [DATE], [HOUR]);

spark.conf.set("spark.databricks.delta.retentionDurationCheck.enabled", "false")

%%sql

VACUUM RAW_SUMMARY RETAIN 0 HOURS;
VACUUM RAW_TRANSACTION RETAIN 0 HOURS;

VACUUM FACT_SUMMARY RETAIN 0 HOURS;
VACUUM FACT_TRANSACTION RETAIN 0 HOURS;