hive "with tbl as" vs "create table tbl as"

Question

1. Does < with tbl as > much faster than < create table tbl as > ?

   with tbl as 
   (
    select 
      id,name 
    from 
      a
   )
   select id from tbl;

   create table tbl 
   as 
   select 
      id,name 
   from 
      a;

   select id from tbl;

2. If I want use tbl in many querys, how to use < with tbl as >?

    with tbl as 
   (
    select 
      id,name 
    from 
      a
   )
   select id from tbl;

   select name from tbl;

Answer 1

1. There's no obvious performance gap.

2. with tbl as is a common table expression, aka CTE, which is only accessible within a single query. So we CAN NOT use CTE across multiple SQL queries separated by ;.

3. Favor create temporary table table over create table. The former is visible within a single session, and will be gone when the session ends.