United121 United121 - 4 years ago 459
Java Question

Impala + parquet file

I have created creating parquet file and then I am trying to import it into Impala table.

I created table as below:

CREATE EXTERNAL TABLE `user_daily` (
`user_id` BIGINT COMMENT 'User ID',
`master_id` BIGINT,
`walletAgency` BOOLEAN,
`zone_id` BIGINT COMMENT 'Zone ID',
`day` STRING COMMENT 'The stats are aggregated for single days',
`clicks` BIGINT COMMENT 'The number of clicks',
`impressions` BIGINT COMMENT 'The number of impressions',
`avg_position` BIGINT COMMENT 'The average position * 100',
`money` BIGINT COMMENT 'The cost of the clicks, in hellers',
`web_id` BIGINT COMMENT 'Web ID',
`discarded_clicks` BIGINT COMMENT 'Number of discarded clicks from column "clicks"',
`impression_money` BIGINT COMMENT 'The cost of the impressions, in hellers'
)
PARTITIONED BY (
year BIGINT,
month BIGINT
)
STORED AS PARQUET
LOCATION '/warehouse/impala/contextstat.db/user_daily/';


Then I copy files there with this schema:

parquet-tools schema user_daily/year\=2016/month\=8/part-r-00001-fd77e1cd-c824-4ebd-9328-0aca5a168d11.snappy.parquet
message spark_schema {
optional int32 user_id;
optional int32 web_id (INT_16);
optional int32 zone_id;
required int32 master_id;
required boolean walletagency;
optional int64 impressions;
optional int64 clicks;
optional int64 money;
optional int64 avg_position;
optional double impression_money;
required binary day (UTF8);
}


And then when I try to see entries with

SELECT * FROM user_daily;


I get

File 'hdfs://.../warehouse/impala/contextstat.db/user_daily/year=2016/month=8/part-r-00000-fd77e1cd-c824-4ebd-9328-0aca5a168d11.snappy.parquet'
has an incompatible Parquet schema for column 'contextstat.user_daily.user_id'.
Column type: BIGINT, Parquet schema:
optional int32 user_id [i:0 d:1 r:0]


Do you know how to solve this problem? I think that BIGINT is the same as int_32. Should I change scheme of table or generating of parquet files?

Answer Source

I use CAST(... AS BIGINT), which change parquet schema from int32 to int64. Then I have to reorder of columns because it wont join then by name. Then it works.

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