UpdateStatisticsForTypeChange(Oid statsOid, Oid relationOid, int attnum,
							  Oid oldColumnType, Oid newColumnType)
{
	/*
	 * Currently, we don't actually need to do anything here.  For both
	 * ndistinct and functional-dependencies stats, the on-disk representation
	 * is independent of the source column data types, and it is plausible to
	 * assume that the old statistic values will still be good for the new
	 * column contents.  (Obviously, if the ALTER COLUMN TYPE has a USING
	 * expression that substantially alters the semantic meaning of the column
	 * values, this assumption could fail.  But that seems like a corner case
	 * that doesn't justify zapping the stats in common cases.)
	 *
	 * Future types of extended stats will likely require us to work harder.
	 */
}
UpdateStatisticsForTypeChange(Oid statsOid, Oid relationOid, int attnum,
							  Oid oldColumnType, Oid newColumnType)
{
	 
}