Hive Explode/横向查看多个阵列 [英] Hive Explode / Lateral View multiple arrays

问题描述

我有一个具有以下架构的配置单元表:

I have a hive table with the following schema:

COOKIE  | PRODUCT_ID | CAT_ID |    QTY    
1234123   [1,2,3]    [r,t,null]  [2,1,null]

如何对数组进行标准化，以便得到以下结果

How can I normalize the arrays so I get the following result

COOKIE  | PRODUCT_ID | CAT_ID |    QTY

1234123   [1]          [r]         [2]

1234123   [2]          [t]         [1] 

1234123   [3]          null       null 

我尝试了以下方法:

select concat_ws('|',visid_high,visid_low) as cookie
,pid
,catid 
,qty
from table
lateral view explode(productid) ptable as pid
lateral view explode(catalogId) ptable2 as catid 
lateral view explode(qty) ptable3 as qty

然而结果是笛卡尔积.

推荐答案

您可以使用 Brickhouse ( http://github.com/klout/brickhouse )来解决这个问题.在 http://brickhouseconfessions.wordpress.com/2013/03/07/exploding-multiple-arrays-at-the-same-time-with-numeric_range/

You can use the numeric_range and array_index UDFs from Brickhouse ( http://github.com/klout/brickhouse ) to solve this problem. There is an informative blog posting describing in detail over at http://brickhouseconfessions.wordpress.com/2013/03/07/exploding-multiple-arrays-at-the-same-time-with-numeric_range/

使用这些 UDF，查询将类似于

Using those UDFs, the query would be something like

select cookie,
   array_index( product_id_arr, n ) as product_id,
   array_index( catalog_id_arr, n ) as catalog_id,
   array_index( qty_id_arr, n ) as qty
from table
lateral view numeric_range( size( product_id_arr )) n1 as n;

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