select nskv1, 
       nskv2, 
       alpha,
       id,
       parent
  from portal.tempVoronogo2

/*+++++++++++++++++++*/
DROP INDEX voronogo_idx1,
DROP INDEX voronogo_idx2,
CREATE INDEX voronogo_idx1 ON portal.tempVoronogo2 (id),
CREATE INDEX voronogo_idx2 ON portal.tempVoronogo2 (parent),
--DROP TABLE portal.tempVoronogo2,
/*+++++++++++++++++++*/
WITH RECURSIVE cte AS (
   SELECT nskv1, 
          nskv2,
          null as nskv3,
          alpha,
          id,
          parent
     FROM portal.tempVoronogo2 
    WHERE parent is null 
   UNION  ALL
   SELECT c.nskv1, 
          c.nskv2,
          t.nskv2 as nskv3,
          t.alpha,
          c.id,
          c.parent
     FROM cte c,
          portal.tempVoronogo2 t 
    WHERE t.parent = c.id
          )
SELECT *
  FROM cte
ORDER BY nskv1
/*+++++++++++++++++++*/