Re: Re: Load Data Parquet Table

[Jeszy]

You can load already existing parquet files to the destination table
from another location in HDFS.

On 12 October 2017 at 18:44, sky  wrote:
> From the impala document, parquet supports load data operation, and how does 
> it support ?
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> At 2017-10-13 00:30:12, "Jeszy"  wrote:
>>See the docs on LOAD DATA:
>>http://impala.apache.org/docs/build/html/topics/impala_load_data.html
>>
>>"In the interest of speed, only limited error checking is done. If the
>>loaded files have the wrong file format, different columns than the
>>destination table, or other kind of mismatch, Impala does not raise
>>any error for the LOAD DATA statement. Querying the table afterward
>>could produce a runtime error or unexpected results. Currently, the
>>only checking the LOAD DATA statement does is to avoid mixing together
>>uncompressed and LZO-compressed text files in the same table."
>>
>>To reload CSV data as parquet using Impala, you'd have to create a
>>table for the CSV data, then do an 'insert into [parquet table] select
>>[...] from [csv_table]'.
>>
>>HTH
>>
>>On 12 October 2017 at 07:58, sky  wrote:
>>> Hi all,
>>> How does the parquet table perform load data operations? How does a CSV 
>>> file import into the parquet table?

Re: Load Data Parquet Table

[Jeszy]

See the docs on LOAD DATA:
http://impala.apache.org/docs/build/html/topics/impala_load_data.html

"In the interest of speed, only limited error checking is done. If the
loaded files have the wrong file format, different columns than the
destination table, or other kind of mismatch, Impala does not raise
any error for the LOAD DATA statement. Querying the table afterward
could produce a runtime error or unexpected results. Currently, the
only checking the LOAD DATA statement does is to avoid mixing together
uncompressed and LZO-compressed text files in the same table."

To reload CSV data as parquet using Impala, you'd have to create a
table for the CSV data, then do an 'insert into [parquet table] select
[...] from [csv_table]'.

HTH

On 12 October 2017 at 07:58, sky  wrote:
> Hi all,
> How does the parquet table perform load data operations? How does a CSV 
> file import into the parquet table?