OPTIMIZE
Optimizes rows in an Apache Iceberg table by rewriting data files into a more optimized layout based on their size and number of associated delete files.
Note
OPTIMIZE is transactional and is supported only for Apache Iceberg
tables.
Syntax
The following syntax summary shows how to optimize data layout for an Iceberg table.
OPTIMIZE [db_name.]table_nameREWRITE DATA USING BIN_PACK [WHEREpredicate]
Note
Only partition columns are allowed in the WHERE clause
predicate. Specifying a non-partition column will
cause the query to fail.
The compaction action is charged by the amount of data scanned during the rewrite
process. The REWRITE DATA action uses predicates to select for files that
contain matching rows. If any row in the file matches the predicate, the file is
selected for optimization. Thus, to control the number of files affected by the
compaction operation, you can specify a WHERE clause.
Configuring compaction properties
To control the size of the files to be selected for compaction and the resulting file size after compaction, you can use table property parameters. You can use the ALTER TABLE SET TBLPROPERTIES command to configure the related table properties.