内在如何加入Presto/AWS雅典娜



我正在尝试执行查询,以选择由另一个表中的启动和结束列定义的范围内的所有行。例如,使用伪代码,如果我有这些(非常小的(表:

ranges:
    group_id = c("a", "b", "c", "d"),
    start = c(1, 7, 2, 25),
    end = c(5, 23, 7, 29)
positions:
    position = 100 random numbers
    annotation = 100 random strings

我想进行一个查询,该查询会返回以下内容:

group_id  position  annotation
a         2         adfkjdas
a         3         sdlfkjasl;kdfj
b         9         sdlfkdj
c         5         wwlekrj
d         27        zxcvzx

使用Mariadb/MySQL,在查询之间将在范围内进行行操作,因此这将有效:

SELECT
      ranges.group_id as group_id,
      positions.position as position,
      positions.annotation as annotation
    FROM
      (SELECT * FROM my_ranges) AS ranges, positions
    WHERE
      positions.position BETWEEN ranges.start AND ranges.end

也就7或25至29之间(。

似乎操作员之间的行为在Presto中的行为不同,因此相同的查询不会返回任何结果。

Realty,我的范围表有约20,000个范围,我想查询约20,000范

这里有人可以建议一种修改此查询(或我的一般方法!(的方法吗?

(在评论中添加(:对于比伪代码更多的SQL,我想

use tables like this:
CREATE TABLE IF NOT EXISTS `ranges` (
  `group_id` char,
  `start` int(3),
  `end` int(3)
);
INSERT INTO `ranges` (`group_id`, `start`, `end`) VALUES
  ('a', '2', '5'),
  ('b', '7', '23'),
  ('c', '2', '7'),
  ('d', '25', '29');
CREATE TABLE IF NOT EXISTS `positions` (
  `position` int(3),
  `annotation` varchar(20)
);
INSERT INTO `positions` (`position`, `annotation`) VALUES
  ('2', 'adfkjdas'),
  ('3', 'sdlfkjasl;kdfj'),
  ('5', 'wwlekrj'),
  ('9', 'sdlfkdj'),
  ('27', 'zxcvzx');

和这样的查询:

SELECT
  group_id,
  position,
  annotation
FROM
  ranges, positions
WHERE
  positions.position BETWEEN ranges.start AND ranges.end

以下对我有用。我必须解决end是一个保留词的事实:

CREATE EXTERNAL TABLE IF NOT EXISTS ranges ( 
  group_id string,
  start_value int,
  end_value int
)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.OpenCSVSerde'
LOCATION 's3://my-bucket/ranges/';
CREATE EXTERNAL TABLE IF NOT EXISTS positions ( 
  position int,
  annotation string
)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.OpenCSVSerde'
LOCATION 's3://my-bucket/positions/';
SELECT
  group_id,
  position,
  annotation
FROM
  ranges, positions
WHERE
  positions.position BETWEEN ranges.start_value AND ranges.end_value;

rangespositions目录包含CSV文件:

a,2,5
b,7,23
c,2,7
d,25,29

2,adfkjdas
3,sdlfkjaslkdfj
5,wwlekrj
9,sdlfkdj
27,zxcvzx

最新更新