Partitioning Historical Data Into Daily Parquet Files in Azure Data Lake Using Azure Data Factory and Azure Notebook
This article explains how to use Azure Data Factory and Azure Notebook to partition historical data into daily Parquet files.
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Join For FreeWhen working with historical data, it is often necessary to partition the data into daily files based on a key column for efficient storage and querying. Azure Data Factory (ADF) provides a powerful data integration service, while Azure Notebook offers an interactive environment for data exploration and analysis. In this article, we will guide you through the process of partitioning historical data into daily Parquet files using Azure Data Factory and an Azure Notebook. This approach allows for easy execution and customization of the partitioning functionality.
Prerequisites
Before proceeding, ensure you have the following:
- An Azure subscription with sufficient privileges to create resources.
- Basic knowledge of Azure Data Factory concepts, such as pipelines, datasets, and linked services.
- Familiarity with notebooks and Python programming.
Step 1: Set Up Azure Data Factory
Create an Azure Data Factory instance and configure the necessary linked services for your data sources (e.g., on-premises databases) and the target Azure Data Lake storage.
Define the required datasets for the source data and target storage.
Create a pipeline that includes a Copy activity to extract data from the source and write it to the staging area.
Step 2: Create an Azure Notebook
Set up an Azure Notebook environment within your Azure subscription.
Create a new notebook and ensure you have the required Python packages installed, including azure-identity, azure-mgmt-datafactory, and pyspark.
Import the necessary packages and authenticate using the Azure Identity library and your Azure credentials.
from azure.identity import DefaultAzureCredential
from azure.mgmt.datafactory import DataFactoryManagementClient
from pyspark.sql import SparkSession
# Authenticate with Azure using default credentials
credential = DefaultAzureCredential()
# Specify the Azure subscription ID
subscription_id = 'YOUR_SUBSCRIPTION_ID'
# Specify the Azure resource group and Data Factory name
resource_group_name = 'YOUR_RESOURCE_GROUP_NAME'
data_factory_name = 'YOUR_DATA_FACTORY_NAME'
# Create a Data Factory client
client = DataFactoryManagementClient(credential, subscription_id)
# Create a SparkSession for data processing
spark = SparkSession.builder.getOrCreate()
Step 3: Partition the Data
Retrieve the necessary parameters for the partitioning process, such as the source table name, target folder path, and key column.
source_table_name = 'YOUR_SOURCE_TABLE_NAME'
target_folder_path = 'YOUR_TARGET_FOLDER_PATH'
key_column = 'YOUR_KEY_COLUMN'
Use the pyspark.sql module to read the data from the staging area into a DataFrame.
staging_data = spark.read.format('delta').load('YOUR_STAGING_AREA_PATH')
Transform the DataFrame by adding a new column representing the partition key (e.g., the date column) using the withColumn
method.
from pyspark.sql.functions import col
partitioned_data = staging_data.withColumn('partition_key', col(key_column).cast('date'))
Partition the DataFrame using the partitionBy
method and the desired key column.
partitioned_data.write.partitionBy('partition_key').parquet(target_folder_path)
Step 4: Execute the Notebook
Run the cells in the notebook to execute the partitioning process.
Monitor the notebook execution for any errors or warnings and review the generated Parquet files in the target folder.
Conclusion
By combining the power of Azure Data Factory and Azure Notebook, you can easily partition historical data into daily.
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