v.23.7Experimental Feature

Writing Parquet Files Now 10x Faster with Multi-threading

Writing parquet files is 10x faster, it's multi-threaded now. Almost the same speed as reading. #49367 (Michael Kolupaev). This is controlled by the setting output_format_parquet_use_custom_encoder which is disabled by default, because the feature is non-ideal.
The performance of writing Parquet files in ClickHouse has been significantly improved with a new multi-threaded encoder, making the write speed nearly as fast as reading.

Why it matters

This feature addresses the slow write performance of Parquet files by introducing a multi-threaded encoding process. It greatly reduces the time required to export data to Parquet format, benefiting users who rely on efficient data serialization and export workflows.

How to use it

To enable the enhanced Parquet write speed, users must set the setting output_format_parquet_use_custom_encoder to true. This setting is disabled by default due to the feature being experimental and potentially non-ideal under certain conditions.