Pratik Khadloya created PARQUET-76:
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Summary: Hive cannot determine the list of columns automatically
based on Parquet serde
Key: PARQUET-76
URL: https://issues.apache.org/jira/browse/PARQUET-76
Project: Parquet
Issue Type: New Feature
Reporter: Pratik Khadloya
Priority: Critical
Today we are not able to create a parquet based hive table without having to
specify the column names and types. When we try to define it the following way,
we get the error
"14/08/20 17:27:46 ERROR ql.Driver: FAILED: SemanticException [Error 10043]:
Either list of columns or a custom serializer should be specified"
{code}
CREATE TABLE parquet_test
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
'/user/pratik/campaigns';
{code}
Whereas if we create a hive table on top of AVRO based files, we do not need to
specify the column names, hive automatically figures out the schema through the
SerDe.
{code}
CREATE EXTERNAL TABLE campaigns
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.avro.AvroSerDe'
STORED AS INPUTFORMAT
'org.apache.hadoop.hive.ql.io.avro.AvroContainerInputFormat'
OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.avro.AvroContainerOutputFormat'
LOCATION '/user/pratik/campaigns'
TBLPROPERTIES ('avro.schema.url'='hdfs:///user/pratik/campaigns.avsc');
{code}
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