> For the complete documentation index, see [llms.txt](https://docs.tonic.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tonic.ai/app/setting-up-your-database/apache-iceberg/iceberg-structural-limitations.md).

# Structural differences and limitations for Apache Iceberg

## Table mode limitations

Apache Iceberg does not support Incremental table mode.

## No subsetting, but support for table filtering

Apache Iceberg workspaces do not support subsetting.

However, for tables that use the De-Identify table mode, you can provide a `WHERE` clause to filter the table. The `WHERE` clause must use DuckDB syntax.

For details, go to [Using table filtering for data warehouses and Spark-based data connectors](/app/generation/subsetting/table-filtering.md).

## No upsert

Apache Iceberg workspaces do not support upsert.

## No output to a container repository

For Apache Iceberg workspaces, you cannot write output to a container repository.

## Post-job scripts require DuckDB

For Apache Iceberg workspaces, any post-job scripts must use DuckDB.


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