> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# weight_lowering_* session settings

> ClickHouse session settings in the weight_lowering_* generated group.

These settings are available in [system.settings](https://clickhouse.com/docs/reference/system-tables/settings.md) and are autogenerated from [source](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp).

## weight\_lowering\_age\_seconds

Type

Double

Default

0

For the `fair` workload scheduler: once the query has been running (wall-clock) for this many seconds, its weight is lowered by `weight_lowering_factor`. `0` (or any negative value) disables the age threshold.

## weight\_lowering\_cpu\_seconds

Type

Double

Default

0

For the `fair` workload scheduler: once the query has attained this many CPU-seconds, its weight is lowered by `weight_lowering_factor`. Applies to CPU resources. `0` (or any negative value) disables the CPU threshold. Attained CPU is the granted scheduler service, charged when a request is granted rather than as CPU is spent, so it leads actual consumption by at most one quantum (`cpu_slot_quantum_ns`) per active slot. This is only meaningful with CPU slot preemption (`cpu_slot_preemption = 1`, the default); without preemption CPU slots carry a fixed per-slot cost rather than real CPU time, so this threshold — like the other `fair` CPU settings — no longer reflects actual CPU consumption.

## weight\_lowering\_factor

Type

Double

Default

1

For the `fair` workload scheduler: once the query crosses any of the `weight_lowering_*` thresholds below, its effective weight is multiplied by this factor once (values in (0, 1) lower the weight, biasing scheduling toward shorter/newer queries). The thresholds do not combine — the first one to trip applies the full lowering. `1.0` disables lowering. The value is clamped to the range `[0, 1]`, so the factor can only ever lower a query's weight, never raise it.

## weight\_lowering\_io\_bytes

Type

Double

Default

0

For the `fair` workload scheduler: once the query has attained this many bytes of IO, its weight is lowered by `weight_lowering_factor`. Applies to IO resources. `0` (or any negative value) disables the IO threshold.