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VACUUM TABLE

When you are working with Apache Iceberg tables, you can use the VACUUM TABLE command to remove older table snapshots that you no longer need and the files (data files, the manifest file, manifest list file, and partition stats files) that are associated only with them. See Expiring Snapshots of Apache Iceberg Tables for more information. Additionally, VACUUM TABLE can clean up orphaned files that may have been left behind in the table location due to failed operations.

To run VACUUM TABLE, users need the OWNERSHIP privilege on the table or must be members of the ADMIN role.

Syntax 
VACUUM TABLE <table_name>
    { EXPIRE SNAPSHOTS [ older_than = <value> ]  [ retain_last = <value> ]
    | REMOVE ORPHAN FILES  [ older_than = <value> ]  [ location = <value> ] }

Parameters​

<table_name> String

The path and name of the table to which the snapshots to expire belong.

EXPIRE SNAPSHOTS [ older_than = <value> ] [ retain_last = <value> ] String   Optional

Options for specifying which snapshots to expire.

  • older_than: Timestamp that marks the lower boundary of the snapshots to keep. Snapshots with timestamps earlier than the specified timestamp are deleted. The default timestamp is five days before the date and time at which the command is run. Only works with UTC timestamps.
  • retain_last: Minimum number of snapshots to retain, starting with the current timestamp.

REMOVE ORPHAN FILES [ older_than = <value> ] [ location = <value> ] String   Optional

Options for specifying which orphan files to remove.

  • older_than: Orphan files with creation timestamps earlier than the specified older_than timestamp are deleted. If no value is provided or the value is less than 3 days, the command defaults to deleting files older than 3 days from the time of execution.
  • location: Specifies the directory to search for orphaned files; defaults to the table’s root location. The location option is not supported for tables stored on HDFS. The specified location must be a subdirectory of the table’s root location.
note

On HDFS, if Dremio users do not have the necessary permissions to access orphaned files, the VACUUM TABLE command will not be able to remove them.

Examples​

Example 1​

Remove snapshots older than specific day and time, but retain a minimum of 20 snapshots 
VACUUM TABLE s3.SF_Incidents2016
    EXPIRE SNAPSHOTS older_than = '2023-04-20 00:00:00.000' retain_last = 20;

Result​

The most recent twenty snapshots are retained. For example, suppose that eleven snapshots are created after the date and time represented by the timestamp. Eight snapshots older than the timestamp are retained, so as to retain the minimum amount of twenty.

This image demonstrates the result of this example.

Example 2​

Remove snapshots older than 5 days, but retain a minimum of 100 snapshots 
VACUUM TABLE s3.SF_Incidents2016 EXPIRE SNAPSHOTS retain_last = 100;

Result​

The most recent one hundred snapshots are retained, even among snapshots that are older than five days. After the 100 snapshots, any snapshots older than 5 days are deleted. For example, suppose that eleven snapshots were created in the past five days. When the command is run, the most recent one hundred snapshots are retained, even though the majority of them were created further back in the past than five days ago.

This image demonstrates the result of this example.

Example 3​

Remove snapshots older than 5 days, but retain a minimum of 1 snapshot 
VACUUM TABLE s3.SF_Incidents2016 EXPIRE SNAPSHOTS;

Result​

The snapshots created within the last five days are retained. For example, suppose that eleven snapshots were created in the last five days. Only those snapshots would be retained.

This image demonstrates the result of this example.

Example 4​

Remove orphan files 
VACUUM TABLE s3.SF_Incidents2016 
   REMOVE ORPHAN FILES OLDER_THAN = '2024-02-15 19:43:53.812';

Result​

The orphan files in the table location that were created before the timestamp specified above are removed.

Limitations​

  • The VACUUM TABLE command is not supported for tables in Arctic catalogs. Use the VACUUM CATALOG command to remove snapshots and orphaned metadata files for tables in Arctic catalog sources.
  • The VACUUM TABLE command does not support Iceberg tables where file paths in metadata use mixed URI schemes or authorities (e.g., a mix of s3a://, s3n://, s3:// or different Azure schemes like abfss://, wasb://).