Merge branch 'main' into fd-snapshots-table-metadata

mkdocs/docs/api.md

@@ -334,6 +334,39 @@ manifest_list: [["s3://warehouse/default/table_metadata_snapshots/metadata/snap-
 summary: [[keys:["added-files-size","added-data-files","added-records","total-data-files","total-delete-files","total-records","total-files-size","total-position-deletes","total-equality-deletes"]values:["5459","1","3","1","0","3","5459","0","0"],keys:["added-files-size","added-data-files","added-records","total-data-files","total-records",...,"total-equality-deletes","total-files-size","deleted-data-files","deleted-records","removed-files-size"]values:["5459","1","3","1","3",...,"0","5459","1","3","5459"],keys:["added-files-size","added-data-files","added-records","total-data-files","total-delete-files","total-records","total-files-size","total-position-deletes","total-equality-deletes"]values:["5459","1","3","2","0","6","10918","0","0"]]]
 ```
 
+### Add Files
+
+Expert Iceberg users may choose to commit existing parquet files to the Iceberg table as data files, without rewriting them.
+
+```
+# Given that these parquet files have schema consistent with the Iceberg table
+
+file_paths = [
+    "s3a://warehouse/default/existing-1.parquet",
+    "s3a://warehouse/default/existing-2.parquet",
+]
+
+# They can be added to the table without rewriting them
+
+tbl.add_files(file_paths=file_paths)
+
+# A new snapshot is committed to the table with manifests pointing to the existing parquet files
+```
+
+<!-- prettier-ignore-start -->
+
+!!! note "Name Mapping"
+    Because `add_files` uses existing files without writing new parquet files that are aware of the Iceberg's schema, it requires the Iceberg's table to have a [Name Mapping](https://iceberg.apache.org/spec/?h=name+mapping#name-mapping-serialization) (The Name mapping maps the field names within the parquet files to the Iceberg field IDs). Hence, `add_files` requires that there are no field IDs in the parquet file's metadata, and creates a new Name Mapping based on the table's current schema if the table doesn't already have one.
+
+<!-- prettier-ignore-end -->
+
+<!-- prettier-ignore-start -->
+
+!!! warning "Maintenance Operations"
+    Because `add_files` commits the existing parquet files to the Iceberg Table as any other data file, destructive maintenance operations like expiring snapshots will remove them.
+
+<!-- prettier-ignore-end -->
+
 ## Schema evolution
 
 PyIceberg supports full schema evolution through the Python API. It takes care of setting the field-IDs and makes sure that only non-breaking changes are done (can be overriden).