# Change data partitioning on Amazon EMR

When [Change Data Partitioning](https://help.qlik.com/en-US/replicate/November2025/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/store_changes_settings.htm#Change) is enabled, the Replicate Change Tables in Hive are partitioned by the `partition_name` column. Data files are uploaded to Amazon S3 storage, according to the [maximum size and time definition](https://help.qlik.com/en-US/replicate/November2025/Content/Replicate/Main/Amazon%20EMR/AmazonEMR_advanced_prop_hadoop_target.htm#Change_process), and then stored in a directory under the Change Table directory. Whenever the specified partition timeframe ends, a partition is created in Hive, pointing to the Amazon S3 storage.

Information about the partitions is written to the [attrep_cdc_partitions](https://help.qlik.com/en-US/replicate/November2025/Content/Global_Common/Content/SharedEMReplicate/Customize%20Tasks/CDC_Partition.htm#control_cdc_part) Control Table.