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hadoopclouderahadoop2cloudera-cdhimpala

Impala minimum DDL

I know that we can create an Impala table like 

CREATE EXTERNAL TABLE SCHEMA.TableName LIKE PARQUET
'/rootDir/SecondLevelDir/RawFileThatKnowsDataTypes.parquet'

But I am not sure if Impala can create a table from a file (preferably a text file) that has no known formatting. So in other words if I just dump a random file into hadoop with a put command, can I wrap an Impala DDL around it and have a table created. Can anyone tell me?

Solution

  • If you file is newline separated I believe it should work if you provide the column delimiter with the ROW FORMAT clause, since textfile is the default format. Just get rid of your LIKE clause, and choose names and datatypes for your columns something like this:

    CREATE EXTERNAL TABLE SCHEMA.TableName (col1 STRING, col2 INT, col3 FLOAT)
'/rootDir/SecondLevelDir/RawFile'
row format delimited fields terminated by ",";