hiveのwith使い方

hiveはwithクエリーでクエリーのパフォーマンスを向上させることができます.with構文でデータをメモリにクエリーし、その後、他のクエリーで直接使用できるためです.
  with   q1  as   (  select   key   from   src  where   key   =  '5' ) select   * from   q1;
  -- from style with   q1  as   ( select   *  from   src  where   key =  '5' ) from   q1 select   *;   -- chaining CTEs with   q1  as   (  select   key   from   q2  where   key   =  '5' ), q2  as   (  select   key   from   src  where   key   =  '5' ) select   *  from   ( select   key   from   q1) a;   -- union example with   q1  as   ( select   *  from   src  where   key =  '5' ), q2  as   ( select   *  from   src s2  where   key   =  '4' ) select   *  from   q1  union   all   select   *  from   q2;


-- insert example create   table   s1  like   src; with   q1  as   (  select   key , value  from   src  where   key   =  '5' ) from   q1 insert   overwrite  table   s1 select   *;
  -- ctas example create   table   s2  as with   q1  as   (  select   key   from   src  where   key   =  '4' ) select   *  from   q1;
  -- view example create   view   v1  as with   q1  as   (  select   key   from   src  where   key   =  '5' ) select   *  from   q1; select   *  from   v1;   -- view example, name collision create   view   v1  as with   q1  as   (  select   key   from   src  where   key   =  '5' ) select   *  from   q1; with   q1  as   (  select   key   from   src  where   key   =  '4' ) select   *  from   v1;