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automatic_parallel_* session settings

These settings are available in system.settings and are autogenerated from source.

automatic_parallel_replicas_min_bytes_per_replica

Experimental feature
Type
UInt64
Default
1048576
Version history
VersionDefault valueComment
26.11048576Better default value derived from testing results
25.120New setting

Threshold of bytes to read per replica to enable parallel replicas automatically (applies only when automatic_parallel_replicas_mode=1). 0 means no threshold. The total number of bytes to read is estimated based on the collected statistics.

automatic_parallel_replicas_mode

Experimental feature
Type
UInt64
Default
0
Version history
VersionDefault valueComment
25.120New setting

Enable automatic switching to execution with parallel replicas based on collected statistics. Requires enable_analyzer = 1, enable_parallel_replicas != 0, parallel_replicas_local_plan = 1 and providing cluster_for_parallel_replicas. 0 - disabled, 1 - enabled, 2 - only statistics collection is enabled (switching to execution with parallel replicas is disabled).

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