Data Lake Partitioning is a crucial optimization technique used to organize data within tables stored in Data Lakes and Data Lakehouses. It involves physically arranging the data files into separate directories (or logical groups managed by a table format) based on the values of one or more specified partition columns (e.g., date, region, customer category).
The primary purpose of partitioning is to enable partition pruning, allowing query engines to significantly improve performance by skipping the reading of irrelevant data files that do not match the query's filter criteria.
Queries on large data lake tables often include filters on specific columns (e.g., 'WHERE event_date = '2023-10-26'' or 'WHERE country = 'US''). Without partitioning, a query engine would potentially have to:
This full scan approach becomes extremely slow and costly on terabyte- or petabyte-scale tables.
Hive-style directory-based partitioning faced several challenges:
Open Table Formats like Apache Iceberg significantly improve upon traditional partitioning:
When RisingWave sinks data into data lake tables, particularly using the Apache Iceberg sink, partitioning is a key consideration:
Choosing effective partition keys based on expected query patterns is crucial when configuring RisingWave to sink data into partitioned lakehouse tables.