v.25.8Improvement

Show the number of ranges

Official CH changelog text
Show the number of ranges to be read in the output of EXPLAIN indexes = 1. #79938 (Christoph Wurm).
Adds the number of ranges to be read in the output of EXPLAIN indexes = 1 to provide more detailed query index usage information.

Why it matters

This feature improves the diagnostic capabilities of ClickHouse by showing how many data ranges will be scanned when using indexes. It helps users better understand and optimize query performance by making index usage more transparent.

How to use it

Users can enable this feature by running EXPLAIN indexes = 1 on their queries. The output will now include the count of ranges to be read, enhancing insight into index effectiveness.

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