Function detect_wraparound 

pub fn detect_wraparound(old_xmin: u32, current_xmin: u32) -> WraparoundCheck

Detect if xmin wraparound has occurred.

PostgreSQL transaction IDs are 32-bit unsigned integers that wrap around after ~4 billion transactions. When this happens, new xmin values will be smaller than old ones by a large margin (> 2 billion).

Arguments

• old_xmin - The previously recorded xmin value
• current_xmin - The current database transaction ID

Returns

WraparoundCheck::WraparoundDetected if wraparound occurred, Normal otherwise.