@Override
	DBFieldIterator keyIterator(Field startField, Field endField, boolean atStart)
			throws IOException {
		return new PrimaryKeyIterator(startField, endField, atStart ? startField : endField,
			atStart ? getPrimaryTableKeyType().getMinValue()
					: getPrimaryTableKeyType().getMaxValue(),
			!atStart);
	}
Delete all primary records which have the current
index value (lastKey).
@see db.DBFieldIterator#delete()
Ghidra/Framework/DB/src/main/java/db/FieldIndexTable.java