Hive / DynamoDB 错误"Could not find column mapping for column"

Question

我正在Amazon Elastic MapReduce EC2实例上运行以下配置单元查询：

CREATE EXTERNAL TABLE myExport (access_key string, active bigint,
    api_id string, secret_key string)
STORED BY 'org.apache.hadoop.hive.dynamodb.DynamoDBStorageHandler'
TBLPROPERTIES ("dynamodb.table.name" = "Authentication",
    "dynamodb.column.mapping" = "access_key:access_key, active:active, api_id:api_id, secret_key:secret_key");

我试图获取Authentication DynamoDB表的内容，但我看到了以下错误：

FAILED: Error in metadata: MetaException(message:Could not find column mapping for column: active)
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask

Answer 1

事实证明，Hive在逗号上拆分后不会修剪DynamoDB列映射，因此列映射列表不能包含空格。

修复：更改逗号加空格（"，"）分隔的列表：

"dynamodb.column.mapping"
    = "access_key:access_key, active:active, api_id:api_id, secret_key:secret_key"

只放入逗号（"，"）分隔的列表：

"dynamodb.column.mapping"
    = "access_key:access_key,active:active,api_id:api_id,secret_key:secret_key"

现在它起作用了。