LATERAL VIEW EXPLODE in presto

Question

New to presto, any pointer how can I use LATERAL VIEW EXPLODE in presto for below table.

I need to filter on names in my presto query

CREATE EXTERNAL TABLE `id`(
 `id` string,
 `names` map<string,map<string,string>>,
 `tags` map<string,map<string,string>>)
ROW FORMAT SERDE
 'org.apache.hadoop.hive.ql.io.parquet.serde.ParquetHiveSerDe' 
STORED AS INPUTFORMAT
 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetInputFormat' 
OUTPUTFORMAT
 'org.apache.hadoop.hive.ql.io.parquet.MapredParquetOutputFormat'
LOCATION
 's3://test'

;

sample names value :

{3081={short=Abbazia 81427 - Milan}, 2057={short=Abbazia 81427 - Milan}, 1033={short=Abbazia 81427 - Milan}, 4105={short=Abbazia 81427 - Milan}, 5129={short=Abbazia 81427 - Milan}}

Answer 1

From the documentation: https://trino.io/docs/current/migration/from-hive.html

Trino (formerly PrestoSQL) supports UNNEST for expanding arrays and maps. Use UNNEST instead of LATERAL VIEW explode().

Hive query:

SELECT student, score
FROM tests
LATERAL VIEW explode(scores) t AS score;

Presto query:

SELECT student, score
FROM tests
CROSS JOIN UNNEST(scores) AS t (score);