Iceberg partition evolution, which is a unique Iceberg feature, and the partition transform feature, greatly simplify partitioning tables and changing partitions.
Partition information is stored in the Iceberg metadata layer, not in the directory structure. You can change the partitioning completely, or just refine existing partitioning, and write new data based on the new partition layout--no need to rewrite existing data files. For example, change a partition by month to a partition by day.
Year, month, and day can be automatically extracted from ‘2023-04-21 20:56:08’ if the table is partitioned by DAY(ts)
SELECT * FROM tbl WHERE ts = ‘2023-04-21 20:56:08’ AND YEAR = 2023 AND MONTH = 4 AND DAY = 21