Vacuum Command

Vacuum command does…​FIXME (see VacuumCommand.gc)

Vacuum command can be executed as VACUUM SQL command or DeltaTable.vacuum operator.

/*
spark-shell \
  --packages io.delta:delta-core_2.12:0.5.0 \
  --conf spark.sql.extensions=io.delta.sql.DeltaSparkSessionExtension
*/

scala> sql("VACUUM delta.`/tmp/delta/t1`").show
Deleted 0 files and directories in a total of 2 directories.
+------------------+
|              path|
+------------------+
|file:/tmp/delta/t1|
+------------------+