v.20.3Experimental Feature

Add New Compact Format for MergeTree Tables to Enhance Insert Performance

Add new compact format of parts in MergeTree-family tables in which all columns are stored in one file. It helps to increase performance of small and frequent inserts. The old format (one file per column) is now called wide. Data storing format is controlled by settings min_bytes_for_wide_part and min_rows_for_wide_part. #8290 (Anton Popov)
Introduces a new compact format for data parts in MergeTree-family tables where all columns are stored in a single file instead of separate files per column.

Why it matters

This feature improves performance for scenarios involving small and frequent inserts by reducing file management overhead compared to the traditional wide format, which stores each column in separate files.

How to use it

Control the data storing format using the settings min_bytes_for_wide_part and min_rows_for_wide_part. Adjusting these settings allows you to switch between the new compact format (single file for all columns) and the legacy wide format (one file per column).