# Considerations and limitations when using Amazon Glue Iceberg REST Catalog APIs
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Following are the considerations and limitations when using the Apache Iceberg REST Catalog Data Definition Language (DDL) operation behavior.

**Considerations**
+  **`RenameTable` API behavior** – The `RenameTable` operation is supported in tables in Amazon Redshift but not in Amazon S3. 
+  **DDL operations for namespaces and tables in Amazon Redshift** – Create, Update, Delete operations for namespaces and tables in Amazon Redshift are asynchronous operations because they are dependent on when Amazon Redshift managed workgroup is available and whether a conflicting DDL and DML transaction is in progress and operation has to wait for lock and then attempt to commit changes. 

**Limitations**
+  View APIs in the Apache Iceberg REST specification are not supported in Amazon Glue Iceberg REST Catalog. 
+  **Iceberg table metadata size limit** – Amazon Glue Data Catalog supports Iceberg tables having a maximum metadata size of 20 MB. Amazon Glue Data Catalog rejects requests to tables with metadata exceeding this limit. To discover tables in Amazon Glue Data Catalog that have metadata size larger than 20 MB, please enable compaction and snapshot retention for tables. For more information, see [Optimizing Iceberg tables](table-optimizers.md).