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Docs: Add rewrite-table-path in spark procedure #12115

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Expand Up @@ -972,4 +972,101 @@ CALL catalog_name.system.compute_table_stats(table => 'my_table', snapshot_id =>
Collect statistics of the snapshot with id `snap1` of table `my_table` for columns `col1` and `col2`
```sql
CALL catalog_name.system.compute_table_stats(table => 'my_table', snapshot_id => 'snap1', columns => array('col1', 'col2'));
```
```

## Table Replication

The `rewrite-table-path` procedure prepares an Iceberg table for moving or copying to another.
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### `rewrite-table-path`

Stages a copy of the Iceberg table's metadata files where every absolute path source prefix is replaced to the specified target.
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This can be the starting point to fully or incrementally copy an Iceberg table located under an absolute path under a
source prefix to another under the target prefix.
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!!! info
This procedure only prepares metadata for an existing Iceberg table in preparation for a copy or move to a new location.
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Copying/Moving metadata and data files to the new location is not part of this procedure.

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| Argument Name | Required? | default | Type | Description |
|--------------------|-----------|------------------------------------------------|--------|-------------------------------------------------------------------------|
| `table` | ✔️ | | string | Name of the table |
| `source_prefix` | ✔️ | | string | The existing prefix to be replaced |
| `target_prefix` | ✔️ | | string | The replacement prefix for `source_prefix` |
| `start_version` | | first metadata.json in table's metadata log | string | The name or path to the chronologically first metadata.json to rewrite. |
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| `end_version` | | latest metadata.json | string | The name or path to the chronologically last metadata.json to rewrite |
| `staging_location` | | new directory under table's metadata directory | string | The output location for newly modified metadata files |


#### Modes of operation:

- Full Rewrite:

By default, the procedure operates in full rewrite mode, rewriting all reachable metadata files. This includes metadata.json, manifest lists, manifests, and position delete files.

- Incremental Rewrite:

If `start_version` is provided, the procedure will only rewrite metadata files created between `start_version` and `end_version`. `end_version` defaults to the latest metadata location of the table.
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#### Output

| Output Name | Type | Description |
|----------------------|--------|-------------------------------------------------------------------------------------|
| `latest_version` | string | Name of the latest metadata file rewritten by this procedure |
| `file_list_location` | string | Path to a file containing a listing of comma-separated source and destination paths |
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##### File List Copy Plan
The file list contains the copy plan for all files added to the table between `startVersion` and `endVersion`.
For each file, it specifies

- Source Path:
The original file path in the table, or the staging location if the file has been rewritten.

- Target Path:
The path with the replacement prefix.

The following example shows a copy plan for three files:

```csv
sourcepath/datafile1.parquet,targetpath/datafile1.parquet
sourcepath/datafile2.parquet,targetpath/datafile2.parquet
stagingpath/manifest.avro,targetpath/manifest.avro
```

#### Examples

Full rewrite of a table's path from source location in HDFS to a target location in S3 bucket of table `my_table`.
This produces a new set of metadata using the s3a prefix in the default staging location under table's metadata directory
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```sql
CALL catalog_name.system.rewrite_table_path(
table => 'db.my_table',
source_prefix => "hdfs://nn:8020/path/to/source_table",
target_prefix => "s3a://bucket/prefix/db.db/my_table"
);
```
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Incremental rewrite of a table's path from a source location to a target location between metadata versions
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`v2.metadata.json` and `v20.metadata.json`, with files written to an explicit staging location

```sql
CALL catalog_name.system.rewrite_table_path(
table => 'db.my_table',
source_prefix => "s3a://bucketOne/prefix/db.db/my_table",
target_prefix => "s3a://bucketTwo/prefix/db.db/my_table",
start_version => "v2.metadata.json",
end_version => "v20.metadata.json",
staging_location => "s3a://bucketStaging/my_table"
);
```

Once the rewrite is completed, third-party tools (
eg. [Distcp](https://hadoop.apache.org/docs/current/hadoop-distcp/DistCp.html)) can be used to copy the newly created
metadata files and data files to the target location

Lastly, [register_table](#register_table) procedure can be used to register copied table in the target location with catalog.
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!!! warning
Iceberg table with statistics files are not currently supported for path rewrite