int getIndexedColumn() {
		return record.getIntValue(COLUMN_INDEXED_COLUMN);
	}
Get the column number which is indexed by this table.
A value of -1 indicates that this is the primary table indexed
by a long key value.  Positive values are used to specify that this 
is a secondary index table, where the Index key corresponds to the
specified column within the named table.
@return int
Ghidra/Framework/DB/src/main/java/db/TableRecord.java