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From wd ...@wdicc.com>
Subject Re: Can hive sql do the same job like this?
Date Sat, 09 Oct 2010 10:30:31 GMT
join_table:
    table_reference JOIN table_factor [join_condition]
  | table_reference {LEFT|RIGHT|FULL} [OUTER] JOIN table_reference
join_condition
  | table_reference LEFT SEMI JOIN table_reference join_condition

table_reference:
    table_factor
  | join_table

table_factor:
    tbl_name [alias]
  | table_subquery alias
  | ( table_references )

join_condition:
    ON equality_expression ( AND equality_expression )*

equality_expression:
    expression = expression


Hive only support equality join.

2010/10/9 Neil Xu <neil.xuxf@gmail.com>

> In oracle,
>
> select a.str1,
>           b.str2
> from ( select str1 from table1) a,
>      ( select str2 from  table2) b
> where instr(a.str1,a.str2) > 0
>
> I know that 'from a, b' is not supported in hive, but table1 and table2
> have no common keys, if 'join' is used, it will be a FULL OUTER JOIN,
> when table1 and table2 have large number of tuples, the task will probably
> fail
>
> so, is there any better way to do the job? Thanks in advance
>
>
> Neil
>

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