Amazon Redshift可以将数据导出为Parquet格式,但不支持直接导出为Avro格式。但是,您可以使用一些中间步骤将数据从Redshift导出为Avro格式。
以下是将数据从Amazon Redshift导出为Parquet格式的代码示例:
import boto3
# 创建Redshift和S3客户端
redshift_client = boto3.client('redshift')
s3_client = boto3.client('s3')
# 定义导出参数
cluster_identifier = 'your-redshift-cluster-identifier'
database_name = 'your-database-name'
table_name = 'your-table-name'
s3_bucket = 'your-s3-bucket'
s3_prefix = 'your-s3-prefix'
parquet_file_name = 'your-parquet-file-name'
# 创建导出任务
response = redshift_client.create_cluster_snapshot(
SnapshotIdentifier='redshift-snapshot',
ClusterIdentifier=cluster_identifier
)
# 等待导出任务完成
redshift_client.get_waiter('cluster_snapshot_available').wait(
SnapshotIdentifier='redshift-snapshot'
)
# 获取导出的快照ID
snapshot_id = response['Snapshot']['SnapshotIdentifier']
# 复制快照到S3
s3_key = f'{s3_prefix}/{parquet_file_name}'
response = redshift_client.copy_cluster_snapshot(
SourceSnapshotIdentifier=snapshot_id,
TargetSnapshotIdentifier=s3_key,
SourceSnapshotClusterIdentifier=cluster_identifier,
TargetBucketName=s3_bucket,
TargetBucketRetentionPeriod=7
)
# 等待快照复制完成
redshift_client.get_waiter('cluster_snapshot_available').wait(
SnapshotIdentifier=s3_key
)
# 导出数据到S3
unload_query = f"UNLOAD ('SELECT * FROM {database_name}.{table_name}') TO 's3://{s3_bucket}/{s3_prefix}/{parquet_file_name}' FORMAT PARQUET"
response = redshift_client.execute_unload(
ClusterIdentifier=cluster_identifier,
Query=unload_query,
S3DestinationConfiguration={
'BucketName': s3_bucket,
'Prefix': f'{s3_prefix}/{parquet_file_name}'
}
)
上述代码示例中,我们首先创建了一个Redshift集群的快照,然后将快照复制到S3存储桶中。接下来,我们使用UNLOAD命令将数据从Redshift导出为Parquet格式,并将其存储在S3中。
要将数据导出为Avro格式,您可以使用以下步骤:
fastavro或avro-python3,将CSV文件转换为Avro格式。以下是将数据从Redshift导出为CSV格式,并将其转换为Avro格式的代码示例:
import boto3
import csv
import fastavro
# 创建Redshift和S3客户端
redshift_client = boto3.client('redshift')
s3_client = boto3.client('s3')
# 定义导出参数
cluster_identifier = 'your-redshift-cluster-identifier'
database_name = 'your-database-name'
table_name = 'your-table-name'
s3_bucket = 'your-s3-bucket'
s3_prefix = 'your-s3-prefix'
csv_file_name = 'your-csv-file-name'
avro_file_name = 'your-avro-file-name'
# 导出数据到CSV文件
unload_query = f"UNLOAD ('SELECT * FROM {database_name}.{table_name}') TO 's3://{s3_bucket}/{s3_prefix}/{csv_file_name}' DELIMITER ',' CSV HEADER"
response = redshift_client.execute_unload(
ClusterIdentifier=cluster_identifier,
Query=unload_query,
S3DestinationConfiguration={
'BucketName': s3_bucket,
'Prefix': f'{s3_prefix}/{csv_file_name}'
}
)
# 下载CSV文件到本地
s3_client.download_file(s3_bucket, f'{s3_prefix}/{csv_file_name}', csv_file_name)
# 转换CSV文件为Avro格式
with open(csv_file_name, 'r') as csv_file, open(avro_file_name, 'wb') as av