v.20.1Improvement
mark_cache_min_lifetime Setting Obsolete, Recommend Increasing mark_cache_size for Performance
The settingsmark_cache_min_lifetimeis now obsolete and does nothing. In previous versions, mark cache can grow in memory larger thanmark_cache_sizeto accomodate data withinmark_cache_min_lifetimeseconds. That was leading to confusion and higher memory usage than expected, that is especially bad on memory constrained systems. If you will see performance degradation after installing this release, you should increase themark_cache_size. #8484 (alexey-milovidov)
Why it matters
Previously, the mark cache could grow beyond the configuredmark_cache_size to accommodate data for the duration of mark_cache_min_lifetime seconds, which caused confusion and increased memory usage, especially on memory-constrained systems. This change removes that behavior to provide more predictable memory usage.How to use it
Themark_cache_min_lifetime setting is now ignored. To avoid potential performance degradation after upgrading, users should adjust the mark_cache_size setting accordingly to ensure sufficient mark cache memory.