> For the complete documentation index, see [llms.txt](https://upsolver.gitbook.io/content/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://upsolver.gitbook.io/content/reference-1/monitoring/datasets/maintenance/compactions.md). # Compactions The **Compactions** tab is visible if you have used the **Iceberg Table Optimizer** to tune your tables, or are using Upsolver to ingest data to Iceberg. To view **Compactions**, from **Datasets**, expand the **navigation tree** to display the table you want to view. If you are only using Upsolver to manage Iceberg tables you have created using another tool, you will only see the tables currently selected for optimization. If you have created pipelines using Upsolver, you will see all your datasets within the navigation tree.

The **Compactions** tab enables you view the size of your files and partitions.

## Compactions The **Compactions** table provides a wealth of information to help you understand where data is being written into your partitions, and where equality and position deletes are occurring.

Metric	Description
Partition	The partition containing some or all of its files undergoing compaction.
Start Time	The start time of the compaction process.
Status	The current status of the compaction process, which can either be Completed, Running, or Failed.
Data Files	The number of data files scheduled for compaction.
Data Files Size	The total size of data files scheduled for compaction.
Output Files	The projected number of data files after the compaction is complete.
In Progress Output Files	The number of target data files currently being compacted.
Successful Output Files	The number of target data files successfully compacted.
Skipped Output Files	The number of target data files aborted during compaction due to deletion applied after the compaction process has begun. The compaction will be rerun on its next schedule.
File Size Reduction	The size reduction achieved by the compaction process. Formula: (Data Files Size + Position Deletes File Size) - Written Bytes.
Equality Deletes Files	The number of equality deletes files to apply while compacting the data. Equality deletes files are files that contain delete commands by primary keys. During the compaction deletes files are being handled.
Equality Deletes Files Size	The total size of Equality Delete Files applied during compaction.
Position Deletes Files Size	The number of position deletes files to apply while compacting the data. Position deletes files are files that contain delete commands by data file name and index.
Read Rows	The number of rows to read from the data files.
Read Bytes	The size in bytes of rows read from the data files.
Written Rows	The number of rows written to the output data files during compaction.
Written Bytes	The size in bytes of data written to the output data files during compaction.
Run Time	The CPU time used for compacting the data. Upsolver parallelizes the compaction process up to the number of output files.

The **Compactions** tab includes a **Search** box to enable you to drill into one or more specific partitions that you want to view statistics for. Type in the name of the partition, or part-name for multiple partitions, and click **Enter**. You can also click on the **Filter** icon to find partitions matching specific metrics. To explore your compaction metrics outside of Upsolver, optionally search or filter for the partitions you want to view, and click the **Download** icon to save the results to a CSV file. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://upsolver.gitbook.io/content/reference-1/monitoring/datasets/maintenance/compactions.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.