title: “Procedures” url: spark-procedures aliases: - “spark/spark-procedures” menu: main: parent: Spark weight: 0

Spark Procedures

To use Iceberg in Spark, first configure Spark catalogs. Stored procedures are only available when using Iceberg SQL extensions in Spark 3.x.

Usage

Procedures can be used from any configured Iceberg catalog with CALL. All procedures are in the namespace system.

CALL supports passing arguments by name (recommended) or by position. Mixing position and named arguments is not supported.

Named arguments

All procedure arguments are named. When passing arguments by name, arguments can be in any order and any optional argument can be omitted.

CALL catalog_name.system.procedure_name(arg_name_2 => arg_2, arg_name_1 => arg_1)

Positional arguments

When passing arguments by position, only the ending arguments may be omitted if they are optional.

CALL catalog_name.system.procedure_name(arg_1, arg_2, ... arg_n)

Snapshot management

`rollback_to_snapshot`

Roll back a table to a specific snapshot ID.

To roll back to a specific time, use rollback_to_timestamp.

{{< hint info >}} This procedure invalidates all cached Spark plans that reference the affected table. {{< /hint >}}

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`snapshot_id`	✔️	long	Snapshot ID to rollback to

Output

Output Name	Type	Description
`previous_snapshot_id`	long	The current snapshot ID before the rollback
`current_snapshot_id`	long	The new current snapshot ID

Example

Roll back table db.sample to snapshot ID 1:

CALL catalog_name.system.rollback_to_snapshot('db.sample', 1)

`rollback_to_timestamp`

Roll back a table to the snapshot that was current at some time.

{{< hint info >}} This procedure invalidates all cached Spark plans that reference the affected table. {{< /hint >}}

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`timestamp`	✔️	timestamp	A timestamp to rollback to

Output

Output Name	Type	Description
`previous_snapshot_id`	long	The current snapshot ID before the rollback
`current_snapshot_id`	long	The new current snapshot ID

Example

Roll back db.sample to a specific day and time.

CALL catalog_name.system.rollback_to_timestamp('db.sample', TIMESTAMP '2021-06-30 00:00:00.000')

`set_current_snapshot`

Sets the current snapshot ID for a table.

Unlike rollback, the snapshot is not required to be an ancestor of the current table state.

{{< hint info >}} This procedure invalidates all cached Spark plans that reference the affected table. {{< /hint >}}

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`snapshot_id`	✔️	long	Snapshot ID to set as current

Output

Output Name	Type	Description
`previous_snapshot_id`	long	The current snapshot ID before the rollback
`current_snapshot_id`	long	The new current snapshot ID

Example

Set the current snapshot for db.sample to 1:

CALL catalog_name.system.set_current_snapshot('db.sample', 1)

`cherrypick_snapshot`

Cherry-picks changes from a snapshot into the current table state.

Cherry-picking creates a new snapshot from an existing snapshot without altering or removing the original.

Only append and dynamic overwrite snapshots can be cherry-picked.

{{< hint info >}} This procedure invalidates all cached Spark plans that reference the affected table. {{< /hint >}}

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`snapshot_id`	✔️	long	The snapshot ID to cherry-pick

Output

Output Name	Type	Description
`source_snapshot_id`	long	The table's current snapshot before the cherry-pick
`current_snapshot_id`	long	The snapshot ID created by applying the cherry-pick

Examples

Cherry-pick snapshot 1

CALL catalog_name.system.cherrypick_snapshot('my_table', 1)

Cherry-pick snapshot 1 with named args

CALL catalog_name.system.cherrypick_snapshot(snapshot_id => 1, table => 'my_table' )

Metadata management

Many maintenance actions can be performed using Iceberg stored procedures.

`expire_snapshots`

Each write/update/delete/upsert/compaction in Iceberg produces a new snapshot while keeping the old data and metadata around for snapshot isolation and time travel. The expire_snapshots procedure can be used to remove older snapshots and their files which are no longer needed.

This procedure will remove old snapshots and data files which are uniquely required by those old snapshots. This means the expire_snapshots procedure will never remove files which are still required by a non-expired snapshot.

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`older_than`	️	timestamp	Timestamp before which snapshots will be removed (Default: 5 days ago)
`retain_last`		int	Number of ancestor snapshots to preserve regardless of `older_than` (defaults to 1)
`max_concurrent_deletes`		int	Size of the thread pool used for delete file actions (by default, no thread pool is used)
`stream_results`		boolean	When true, deletion files will be sent to Spark driver by RDD partition (by default, all the files will be sent to Spark driver). This option is recommended to set to `true` to prevent Spark driver OOM from large file size

If older_than and retain_last are omitted, the table's expiration properties will be used.

Output

Output Name	Type	Description
`deleted_data_files_count`	long	Number of data files deleted by this operation
`deleted_manifest_files_count`	long	Number of manifest files deleted by this operation
`deleted_manifest_lists_count`	long	Number of manifest List files deleted by this operation

Examples

Remove snapshots older than specific day and time, but retain the last 100 snapshots:

CALL hive_prod.system.expire_snapshots('db.sample', TIMESTAMP '2021-06-30 00:00:00.000', 100)

`remove_orphan_files`

Used to remove files which are not referenced in any metadata files of an Iceberg table and can thus be considered “orphaned”.

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to clean
`older_than`	️	timestamp	Remove orphan files created before this timestamp (Defaults to 3 days ago)
`location`		string	Directory to look for files in (defaults to the table's location)
`dry_run`		boolean	When true, don't actually remove files (defaults to false)
`max_concurrent_deletes`		int	Size of the thread pool used for delete file actions (by default, no thread pool is used)

Output

Output Name	Type	Description
`orphan_file_location`	String	The path to each file determined to be an orphan by this command

Examples

List all the files that are candidates for removal by performing a dry run of the remove_orphan_files command on this table without actually removing them:

CALL catalog_name.system.remove_orphan_files(table => 'db.sample', dry_run => true)

Remove any files in the tablelocation/data folder which are not known to the table db.sample.

CALL catalog_name.system.remove_orphan_files(table => 'db.sample', location => 'tablelocation/data')

`rewrite_data_files`

Iceberg tracks each data file in a table. More data files leads to more metadata stored in manifest files, and small data files causes an unnecessary amount of metadata and less efficient queries from file open costs.

Iceberg can compact data files in parallel using Spark with the rewriteDataFiles action. This will combine small files into larger files to reduce metadata overhead and runtime file open cost.

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`strategy`		string	Name of the strategy - binpack or sort. Defaults to binpack strategy
`sort_order`		string	If Zorder, then comma separated column names within zorder() text. Example: zorder(c1,c2,c3). Else, Comma separated sort_order_column. Where sort_order_column is a space separated sort order info per column (ColumnName SortDirection NullOrder). SortDirection can be ASC or DESC. NullOrder can be NULLS FIRST or NULLS LAST
`options`	️	map<string, string>	Options to be used for actions
`where`	️	string	predicate as a string used for filtering the files. Note that all files that may contain data matching the filter will be selected for rewriting

See the [RewriteDataFiles Javadoc](../../../javadoc/{{% icebergVersion %}}/org/apache/iceberg/actions/RewriteDataFiles.html#field.summary),
[BinPackStrategy Javadoc](../../../javadoc/{{% icebergVersion %}}/org/apache/iceberg/actions/BinPackStrategy.html#field.summary) and
[SortStrategy Javadoc](../../../javadoc/{{% icebergVersion %}}/org/apache/iceberg/actions/SortStrategy.html#field.summary) for list of all the supported options for this action.

Output

Output Name	Type	Description
`rewritten_data_files_count`	int	Number of data which were re-written by this command
`added_data_files_count`	int	Number of new data files which were written by this command

Examples

Rewrite the data files in table db.sample using the default rewrite algorithm of bin-packing to combine small files and also split large files according to the default write size of the table.

CALL catalog_name.system.rewrite_data_files('db.sample')

Rewrite the data files in table db.sample by sorting all the data on id and name using the same defaults as bin-pack to determine which files to rewrite.

CALL catalog_name.system.rewrite_data_files(table => 'db.sample', strategy => 'sort', sort_order => 'id DESC NULLS LAST,name ASC NULLS FIRST')

Rewrite the data files in table db.sample by zOrdering on column c1 and c2. Using the same defaults as bin-pack to determine which files to rewrite.

CALL catalog_name.system.rewrite_data_files(table => 'db.sample', strategy => 'sort', sort_order => 'zorder(c1,c2)')

Rewrite the data files in table db.sample using bin-pack strategy in any partition where more than 2 or more files need to be rewritten.

CALL catalog_name.system.rewrite_data_files(table => 'db.sample', options => map('min-input-files','2'))

Rewrite the data files in table db.sample and select the files that may contain data matching the filter (id = 3 and name = “foo”) to be rewritten.

CALL catalog_name.system.rewrite_data_files(table => 'db.sample', where => 'id = 3 and name = "foo"')

`rewrite_manifests`

Rewrite manifests for a table to optimize scan planning.

Data files in manifests are sorted by fields in the partition spec. This procedure runs in parallel using a Spark job.

See the [RewriteManifests Javadoc](../../../javadoc/{{% icebergVersion %}}/org/apache/iceberg/actions/RewriteManifests.html) to see more configuration options.

{{< hint info >}} This procedure invalidates all cached Spark plans that reference the affected table. {{< /hint >}}

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to update
`use_caching`	️	boolean	Use Spark caching during operation (defaults to true)

Output

Output Name	Type	Description
`rewritten_manifests_count`	int	Number of manifests which were re-written by this command
`added_mainfests_count`	int	Number of new manifest files which were written by this command

Examples

Rewrite the manifests in table db.sample and align manifest files with table partitioning.

CALL catalog_name.system.rewrite_manifests('db.sample')

Rewrite the manifests in table db.sample and disable the use of Spark caching. This could be done to avoid memory issues on executors.

CALL catalog_name.system.rewrite_manifests('db.sample', false)

Table migration

The snapshot and migrate procedures help test and migrate existing Hive or Spark tables to Iceberg.

`snapshot`

Create a light-weight temporary copy of a table for testing, without changing the source table.

The newly created table can be changed or written to without affecting the source table, but the snapshot uses the original table's data files.

When inserts or overwrites run on the snapshot, new files are placed in the snapshot table's location rather than the original table location.

When finished testing a snapshot table, clean it up by running DROP TABLE.

{{< hint info >}} Because tables created by snapshot are not the sole owners of their data files, they are prohibited from actions like expire_snapshots which would physically delete data files. Iceberg deletes, which only effect metadata, are still allowed. In addition, any operations which affect the original data files will disrupt the Snapshot's integrity. DELETE statements executed against the original Hive table will remove original data files and the snapshot table will no longer be able to access them. {{< /hint >}}

See migrate to replace an existing table with an Iceberg table.

Usage

Argument Name	Required?	Type	Description
`source_table`	✔️	string	Name of the table to snapshot
`table`	✔️	string	Name of the new Iceberg table to create
`location`		string	Table location for the new table (delegated to the catalog by default)
`properties`	️	map<string, string>	Properties to add to the newly created table

Output

Output Name	Type	Description
`imported_files_count`	long	Number of files added to the new table

Examples

Make an isolated Iceberg table which references table db.sample named db.snap at the catalog's default location for db.snap.

CALL catalog_name.system.snapshot('db.sample', 'db.snap')

Migrate an isolated Iceberg table which references table db.sample named db.snap at a manually specified location /tmp/temptable/.

CALL catalog_name.system.snapshot('db.sample', 'db.snap', '/tmp/temptable/')

`migrate`

Replace a table with an Iceberg table, loaded with the source's data files.

Table schema, partitioning, properties, and location will be copied from the source table.

Migrate will fail if any table partition uses an unsupported format. Supported formats are Avro, Parquet, and ORC. Existing data files are added to the Iceberg table's metadata and can be read using a name-to-id mapping created from the original table schema.

To leave the original table intact while testing, use snapshot to create new temporary table that shares source data files and schema.

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to migrate
`properties`	️	map<string, string>	Properties for the new Iceberg table

Output

Output Name	Type	Description
`migrated_files_count`	long	Number of files appended to the Iceberg table

Examples

Migrate the table db.sample in Spark's default catalog to an Iceberg table and add a property ‘foo’ set to ‘bar’:

CALL catalog_name.system.migrate('spark_catalog.db.sample', map('foo', 'bar'))

Migrate db.sample in the current catalog to an Iceberg table without adding any additional properties:

CALL catalog_name.system.migrate('db.sample')

`add_files`

Attempts to directly add files from a Hive or file based table into a given Iceberg table. Unlike migrate or snapshot, add_files can import files from a specific partition or partitions and does not create a new Iceberg table. This command will create metadata for the new files and will not move them. This procedure will not analyze the schema of the files to determine if they actually match the schema of the Iceberg table. Upon completion, the Iceberg table will then treat these files as if they are part of the set of files owned by Iceberg. This means any subsequent expire_snapshot calls will be able to physically delete the added files. This method should not be used if migrate or snapshot are possible.

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Table which will have files added to
`source_table`	✔️	string	Table where files should come from, paths are also possible in the form of `file_format`.`path`
`partition_filter`	️	map<string, string>	A map of partitions in the source table to import from

Warning : Schema is not validated, adding files with different schema to the Iceberg table will cause issues.

Warning : Files added by this method can be physically deleted by Iceberg operations

Examples

Add the files from table db.src_table, a Hive or Spark table registered in the session Catalog, to Iceberg table db.tbl. Only add files that exist within partitions where part_col_1 is equal to A.

CALL spark_catalog.system.add_files(
table => 'db.tbl',
source_table => 'db.src_tbl',
partition_filter => map('part_col_1', 'A')
)

Add files from a parquet file based table at location path/to/table to the Iceberg table db.tbl. Add all files regardless of what partition they belong to.

CALL spark_catalog.system.add_files(
  table => 'db.tbl',
  source_table => '`parquet`.`path/to/table`'
)

`Metadata information`

`ancestors_of`

Report the live snapshot IDs of parents of a specified snapshot

Usage

Argument Name	Required?	Type	Description
`table`	✔️	string	Name of the table to report live snapshot IDs
`snapshot_id`	️	long	Use a specified snapshot to get the live snapshot IDs of parents

tip : Using snapshot_id
Given snapshots history with roll back to B and addition of C' -> D'
A -> B - > C -> D
      \ -> C' -> (D')
Not specifying the snapshot ID would return A -> B -> C' -> D', while providing the snapshot ID of D as an argument would return A-> B -> C -> D

Output

Output Name	Type	Description
`snapshot_id`	long	the ancestor snapshot id
`timestamp`	long	snapshot creation time

Examples

Get all the snapshot ancestors of current snapshots(default)

CALL spark_catalog.system.ancestors_of('db.tbl')

Get all the snapshot ancestors by a particular snapshot

CALL spark_catalog.system.ancestors_of('db.tbl', 1)
CALL spark_catalog.system.ancestors_of(snapshot_id => 1, table => 'db.tbl')