static List*
get_columnnames( List* candidates )
{
	int proc;
	int ret;
	StringInfoData	query;	/* string for Query */
	StringInfoData	cols;	/* string for Columns */
	MemoryContext outerContext;
	ListCell		*cell;
    

	
	
	IndexCandidate* idxcd;
	

	elog( DEBUG3, "IND ADV: get_column_names: ENTER" );

	

	
	initStringInfo( &query );
	initStringInfo( &cols );
	
	foreach( cell, candidates ) /* foreach cell in candidates */
	{
						
		int i;
		
		
	
	    /*elog (INFO, "Ingresando a foreach");*/
		idxcd = (IndexCandidate*)lfirst( cell );
		
		if (idxcd == NULL) {
            elog( INFO, "idxcd IS NULL" );
            continue; /* Or is that fatal enough to break instead? */
        }

        if (!idxcd->idxused)
            continue;
			
			
	

			/* pfree() the memory allocated for the previous candidate. FIXME: Avoid
		 	* meddling with the internals of a StringInfo, and try to use an API.
		 	*/
			if( cols.len > 0 )
			{
				initStringInfo(&cols);
			} /*IF col.len>0*/
			
			if( query.len > 0 )
			{
				initStringInfo(&query);
			} /*IF col.len>0*/

			elog(INFO,"reloid:%d", idxcd->reloid);
			appendStringInfo( &query, "select a.attname from pg_class c,pg_attribute a where c.oid=%d AND a.attrelid = c.oid AND (", idxcd->reloid);
			
			/*elog(INFO,"QUERY:%s", query.data);*/
			
			/*elog(INFO,"ncols:%d", idxcd->ncols);*/
		
			for (i = 0; i < idxcd->ncols; ++i)
			{
				/*elog(INFO,"i:%d", i);*/
				/*elog(INFO,"var attno i:%d", idxcd->varattno[i]);*/
				/*elog(INFO,"cols:%s", cols.data);*/
				appendStringInfo( &cols, "%s a.attnum=%d", (i>0 ? " OR" : ""), idxcd->varattno[i]);
				/*elog(INFO,"cols:%s", cols.data);*/
				/*elog(INFO,"i:%d", i);*/
			    elog(INFO,"varattno i:%d", idxcd->varattno[i]);

		
			}/* foreach col in varattno*/
		
			/*elog(INFO,"PASA EL FOR");*/
			appendStringInfo( &cols, "%s", ")");
		
			/* FIXME: Mention the column names explicitly after the table name. */
			appendStringInfo( &query, "%s;", cols.data);
		
			elog(INFO,"QUERY:%s", query.data);
			/*elog(INFO,"LONGITUD:%d", query.len);*/
		    							
			if( query.len > 0 )	/* if we generated any SQL */
			{
			
				
				outerContext = CurrentMemoryContext;
				if( SPI_connect() == SPI_OK_CONNECT )
				{
					/*elog(INFO,"CONECTADO:%d", query.len);*/
				
			    	ret=SPI_exec(query.data, 0);
			    	proc=SPI_processed;
			    	TupleDesc tupdesc=SPI_tuptable->tupdesc;
			    	SPITupleTable *tuptable=SPI_tuptable;
			    	char buf[8192];
					if( ret>0 )
					{
					    /*elog(INFO,"EJECUTA:%d", query.len);*/
					
					
						if( SPI_tuptable != NULL)
				   		 {
				   		 	
							//TupleDesc tupdesc;
							
							//SPITupleTable *tuptable = SPI_tuptable;
							
							//tupdesc = tuptable->tupdesc;
							
							
							elog(INFO,"procantesciclo:%d", proc);
							int i,j;
							for(j=0;j<proc;j++)
							{
								HeapTuple tuple;
								elog(INFO,"procdespuesciclo:%d", proc);
								/*cada fila*/
								int cont=0;
								tuple=tuptable->vals[j];	
								if (tuple!=NULL)
								{
									
									for (i=1,buf[0]=0;i<=tupdesc->natts;i++)
									{
										char *data;
									
						    			/* cada columna de cada fila*/
										
										data=SPI_getvalue(tuple,tupdesc,i);
										elog(INFO,"data:%s", data);
										
	    								
										idxcd->varattnombres[i]=MemoryContextStrdup(outerContext, data);
										
										elog(INFO,"valorgc:%s", idxcd->varattnombres[i]);
										elog(INFO,"indice:%d", cont);
										cont++;
										snprintf(buf + strlen (buf), sizeof(buf) - strlen(buf), " %s%s", SPI_getvalue(tuple, tupdesc, i),(i == tupdesc->natts) ? " " : " |");
						
									} /* (i=0,buf[0]=0;i<tupdesc->natts;i++)*/
									elog (INFO, "EXECQ: %s", buf);
								} /* if (tuple!=null)*/
								else
									elog( WARNING, "IND ADV: tuple is null." );
						}	/* (j=0;j<proc;j++)*/
					}	/*if( SPI_tuptable != NULL)*/
					else
						elog( WARNING, "IND ADV: SPI_tuptable is null." );
			    }
			    else    
			    	  elog( WARNING, "IND ADV: SPI_execute failed while select." );
			    if( SPI_finish() != SPI_OK_FINISH )
				elog( WARNING, "IND ADV: SPI_finish failed while select." );
				
			} /*if( SPI_connect() == SPI_OK_CONNECT )*/			

			else
			elog( WARNING, "IND ADV: SPI_connect failed while select." );
	
	
					
			} /*if( query.len > 0 )*/
			elog (INFO, "if( query.len > 0");
				
			/*if( query.len > 0 )*/
			
	}	/* foreach cell in candidates */
	elog (INFO, "/* foreach cell in candidates */");		
		
	foreach( cell, candidates ) /* foreach cell in candidates */
	{
	
		
	    MemoryContext oldContext = MemoryContextSwitchTo( outerContext );
		MemoryContextSwitchTo( oldContext );	
		
	    
		/*elog (INFO, "Ingresando a foreach");*/
		idxcd = (IndexCandidate*)lfirst( cell );
		
		if (idxcd == NULL) {
            elog( INFO, "idxcd IS NULL" );
            continue; /* Or is that fatal enough to break instead? */
        }

        if (!idxcd->idxused)
            continue;
			
			
			int i;	
			for (i = 0; i < idxcd->ncols; ++i)
			{
				
				/*elog(INFO,"cols:%s", cols.data);*/
				elog(INFO,"i:%d", i);
			    elog(INFO,"varattnombres i:%s", idxcd->varattnombres[i]);
			    elog(INFO,"varattno i:%d", idxcd->varattno[i]);

		
			}/* foreach col in varattno*/
		
	}
	
		
	/* TODO: Propose to -hackers to introduce API to free a StringInfoData . */
	if ( query.len > 0 )
		pfree( query.data );
	
	
	elog( DEBUG3, "IND ADV: select: EXIT" );
	elog (INFO, "retornando get_columnnames");
	return candidates;
}