Json data into hive heap size error - json

Question

I am working on nested json data which i got from facebook using nifi. i have creating a table in hive and loading the data using the command.
CREATE TABLE abmediaanalysis (id string, posts struct< data:array<struct< message:string, shares:struct< count:int>, id:string, reactions:struct< data:array<struct< name:string,id:string>>, paging:struct< cursors:struct< before:string,after:string>, next:string>>, likes:struct< data:array<struct< id:string>>, paging:struct< cursors:struct< before:string,after:string>, next:string>>>>, paging:struct< previous:string,next:string>>, feed struct< data:array<struct< permalink_url:string,message:string,id:string>>, paging:struct< previous:string,next:string>>)ROW FORMAT SERDE 'org.openx.data.jsonserde.JsonSerDe';
load data local inpath '/home/10879/facebook1480479682880.json' overwrite into table abmediaanalysis;
i have also added the jar file json-serde-1.3.8-jar-with-dependencies.jar,
but when i am using lateral view explode to print all the columns, i am getting java heap size error. i have also increased the heap size but still same error
select id,posts_message,posts_share_count,posts_id,feed_data_permalink_url,feed_data_message,feed_data_id,reaction_data_name,reaction_data_id,posts_likes_data_id from abmediaanalysis
LATERAL VIEW explode(posts.data.message)MSG as posts_message
LATERAL VIEW explode(posts.data.shares.count)CT as posts_share_count
LATERAL VIEW explode(posts.data.id) I as posts_id
LATERAL VIEW explode(feed.data.permalink_url) PU as feed_data_permalink_url
LATERAL VIEW explode(feed.data.message) MSG as feed_data_message
LATERAL VIEW explode(feed.data.id) I as feed_data_id
LATERAL VIEW explode(posts.data.reactions) NM as posts_reactions_name
LATERAL VIEW explode(posts_reactions_name.data.name) NM as reaction_data_name
LATERAL VIEW explode(posts_reactions_name.data.id) NM as reaction_data_id
LATERAL VIEW explode(posts.data.likes) I as likes_data_id
LATERAL VIEW explode(likes_data_id.data.id) I as posts_likes_data_id;
when i tried to print two or three columns instead of showing 616 records its showing 15625 records approx.
Can anyone help with this issue
Is there a chance to load the above json data directly from nifi into hive table? if so can you tell me.
Thanks in advance

Answer 1

If I may suggest you another approach to just load the whole JSON string into a column as String datatype into an external table.
e.g.
CREATE EXTERNAL TABLE json_data_table (
id String,
json_data String
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY '\u0001' LINES TERMINATED BY '\n' STORED AS TEXTFILE
LOCATION '/path/to/json';
Use Hive get_json_object to extract individual columns. E.g.
If json_data column has below JSON string
{"store":
{"fruit":\[{"weight":8,"type":"apple"},{"weight":9,"type":"pear"}],
"bicycle":{"price":19.95,"color":"red"}
},
"email":"amy#only_for_json_udf_test.net",
"owner":"amy"
}
The below query fetches
SELECT get_json_object(json_data, '$.owner') FROM json_data_table;
returns amy
In this way you could extract each json element as column from the table.