v.25.6Improvement

PR addresses issues with the implementation

Official CH changelog text
This PR addresses issues with the implementation of is_strict in the monotonicity checks for conversion functions. Currently, some conversion functions, such as toFloat64(UInt32) and toDate(UInt8), incorrectly return is_strict as false when they should return true. #81359 (zoomxi).
Fix strict monotonicity detection for conversion functions in ClickHouse.

Why it matters

The feature corrects the evaluation of is_strict in monotonicity checks for certain conversion functions like toFloat64(UInt32) and toDate(UInt8). Previously, these functions incorrectly returned is_strict as false, which could affect query optimizations relying on monotonicity assumptions. Ensuring accurate strict monotonicity detection improves query planner decisions and performance.

How to use it

This fix is applied internally within ClickHouse's monotonicity checks and requires no user action. Users will benefit automatically from improved query optimization behavior after upgrading to the version including this fix.

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