# Enabling compaction optimizer You can use AWS Glue console, AWS CLI, or AWS API to enable compaction for your Apache Iceberg tables in the AWS Glue Data Catalog. For new tables, you can choose Apache Iceberg as table format and enable compaction when you create the table. Compaction is disabled by default for new tables. ------ #### [ Console ] **To enable compaction** 1. Open the AWS Glue console at [https://console.aws.amazon.com/glue/](https://console.aws.amazon.com/glue/) and sign in as a data lake administrator, the table creator, or a user who has been granted the `glue:UpdateTable` and `lakeformation:GetDataAccess` permissions on the table. 1. In the navigation pane, under **Data Catalog**, choose **Tables**. 1. On the **Tables** page, choose a table in open table format that you want to enable compaction for, then under **Actions** menu, choose **Optimization**, and then choose **Enable**. You can also enable compaction by selecting the **Table optimization** tab on the **Table details** page. Choose the **Table optimization** tab on the lower section of the page, and choose **Enable compaction**. The **Enable optimization** option is also available when you create a new Iceberg table in the Data Catalog. 1. On the **Enable optimization** page, choose **Compaction** under **Optimization options**. ![\[Apache Iceberg table details page with Enable compaction option.\]](http://docs.aws.amazon.com/glue/latest/dg/images/table-enable-compaction.png) 1. Next, select an IAM role from the drop down with the permissions shown in the [Table optimization prerequisites](optimization-prerequisites.md) section. You can also choose **Create a new IAM role** option to create a custom role with the required permissions to run compaction. Follow the steps below to update an existing IAM role: 1. To update the permissions policy for the IAM role, in the IAM console, go to the IAM role that is being used for running compaction. 1. In the **Add permissions** section, choose Create policy. In the newly opened browser window, create a new policy to use with your role. 1. On the Create policy page, choose the `JSON` tab. Copy the JSON code shown in the Prerequisites into the policy editor field. 1. If you have security policy configurations where the Iceberg table optimizer needs to access Amazon S3 buckets from a specific Virtual Private Cloud (VPC), create an AWS Glue network connection or use an existing one. If you don't have an AWS Glue VPC connection set up already, create a new one by following the steps in the [Creating connections for connectors](https://docs.aws.amazon.com/glue/latest/dg/creating-connections.html) section using the AWS Glue console or the AWS CLI/SDK. 1. Choose a compaction strategy. The available options are: + **Binpack** – Binpack is the default compaction strategy in Apache Iceberg. It combines smaller data files into larger ones for optimal performance. + **Sort** – Sorting in Apache Iceberg is a data organization technique that clusters information within files based on specified columns, significantly improving query performance by reducing the number of files that need to be processed. You define the sort order in Iceberg's metadata using the sort-order field, and when multiple columns are specified, data is sorted in the sequence the columns appear in the sort order, ensuring records with similar values are stored together within files. The sorting compaction strategy takes the optimization further by sorting data across all files within a partition. + **Z-order** – Z-ordering is a way to organize data when you need to sort by multiple columns with equal importance. Unlike traditional sorting that prioritizes one column over others, Z-ordering gives balanced weight to each column, helping your query engine read fewer files when searching for data. The technique works by weaving together the binary digits of values from different columns. For example, if you have the numbers 3 and 4 from two columns, Z-ordering first converts them to binary (3 becomes 011 and 4 becomes 100), then interleaves these digits to create a new value: 011010. This interleaving creates a pattern that keeps related data physically close together. Z-ordering is particularly effective for multi-dimensional queries. For example, a customer table Z-ordered by income, state, and zip code can deliver superior performance compared to hierarchical sorting when querying across multiple dimensions. This organization allows queries targeting specific combinations of income and geographic location to quickly locate relevant data while minimizing unnecessary file scans. 1. **Minimum input files **– The number of data files required in a partition before compaction is triggered. 1. **Delete files threshold** – Minimum delete operations required in a data file before it becomes eligible for compaction. 1. Choose **Enable optimization**. ------ #### [ AWS CLI ] The following example shows how to enable compaction. Replace the account ID with a valid AWS account ID. Replace the database name and table name with actual Iceberg table name and the database name. Replace the `roleArn` with the AWS Resource Name (ARN) of the IAM role and name of the IAM role that has the required permissions to run compaction. You can replace compaction strategy `sort` with other supported strategies like `z-order` or `binpack`. order" depending on your requirements. ``` aws glue create-table-optimizer \ --catalog-id 123456789012 \ --database-name iceberg_db \ --table-name iceberg_table \ --table-optimizer-configuration '{ "roleArn": "arn:aws:iam::123456789012:role/optimizer_role", "enabled": true, "vpcConfiguration": {"glueConnectionName": "glue_connection_name"}, "compactionConfiguration": { "icebergConfiguration": {"strategy": "sort"} } }'\ --type compaction ``` ------ #### [ AWS API ] Call [CreateTableOptimizer](https://docs.aws.amazon.com/glue/latest/dg/aws-glue-api-table-optimizers.html#aws-glue-api-table-optimizers-CreateTableOptimizer) operation to enable compaction for a table. ------ After you enable compaction, **Table optimization** tab shows the following compaction details once the compaction run is complete: Start time The time at which the compaction process started within Data Catalog. The value is a timestamp in UTC time. End time The time at which the compaction process ended in Data Catalog. The value is a timestamp in UTC time. Status The status of the compaction run. Values are success or fail. Files compacted Total number of files compacted. Bytes compacted Total number of bytes compacted.