System Variables | Description | Parameter Type | Default Value | Value Range | Scope | Support for SET_VAR Hint |
libra_enable_runtime_filter | Specifies whether to enable the Runtime filter. | BOOL | ON | ON: Enables the Runtime filter. OFF: Disables the Runtime filter. | Global & Session | Yes |
libra_runtime_filter_type | Sets the Runtime filter types that can be assigned. | VARCHAR | MIN_MAX, BLOOM_FILTER, and IN_FILTER | BLOOM_FILTER: Builds a Bloom Filter on the JOIN key from the Build side to filter data on the Probe side. MIN_MAX: Builds the minimum and maximum values of the JOIN key from the Build side to filter data on the Probe side. IN: Builds a value list of the JOIN key from the Build side to filter data on the Probe side. Empty string: Indicates that the Runtime Filter feature is disabled. | Global & Session | Yes |
libra_enable_cost_based_runtime_filter | Enables/Disables the cost-based Runtime filter. | BOOL | ON | ON: Enables the cost-based Runtime filter assignment. OFF: Disables cost-based Runtime Filter assignment. | Global & Session | Yes |
libra_max_in_runtime_filter_ndv | The maximum NDV (Number of Distinct Values) on the BUILD side when a Runtime filter of type IN is generated in the cost-based Runtime filter. | INT | 1024 | 0 - MaxValue | Global & Session | Yes |
runtime_filter_wait_time_ms | Indicates the maximum time to wait for RF Ready for the first time on the RF USE side, where 0 means waiting indefinitely until timeout or interrupting the query execution. | INT | 100 | [0, MaxValue). | Global & Session | Yes |
System Variables | Description | Parameter Type | Default Value | Value Range | Scope | Support for SET_VAR Hint |
libra_enable_late_materialization | Specifies whether to enable the late materialization. | BOOL | OFF | ON: Enables the late materialization. OFF: Disables the late materialization. | Global & Session | Yes |
System Variables | Description | Parameter Type | Default Value | Value Range | Scope | Support for SET_VAR Hint |
max_threads | Queries the parallelism during the execution. | INT | The number of CPU cores in a node | 0 - MaxValue (recommended not to exceed twice the number of CPU cores). | Global & Session | Yes |
System Variables | Description | Parameter Type | Default Value | Value Range | Scope | Support for SET_VAR Hint |
max_bytes_before_external_agg_uniq_exact | When the count distinct is using the calculation function uniqExactDisk, if the hashset exceeds this limit, it starts to switch to external memory. The default value is 0, which means no external memory calculation is performed. | INT | 0 | [0, MaxValue). | Global & Session | Yes |
one_bucket_max_temp_file_size | The maximum size of each file allowed to be stored into the bucket when the count distinct is using the calculation function uniqExactDisk. When this size is exceeded, it is necessary to switch to a new file to write. | INT | 0 | [0, MaxValue). | Global & Session | Yes |
count_distinct_implementation | The name of the function the count distinct uses for calculation. By default, uniqExactDisk is used. | VARCHAR | uniqExactDisk | uniqExactDisk: An accurate CountDistinct calculation method with the storage feature. uniq: An approximate CountDistinct calculation method. uniqExact: An accurate CountDistinct calculation method for pure memory. | - | Yes |
join_build_concurrency | Specify the parallelism used for the join build. The default value is 0, which means using the default value or specifying the MaxThreads. | INT | 0 | [0, MaxValue). | Global & Session | Yes |
enable_local_tunnel | Supports communication optimization of the local sender and receiver. | BOOL | ON | ON: Enables the local channel local communication optimization. OFF: Disables the local channel local communication optimization. | Global & Session | Yes |
mpp_max_packet_size | The maximum size of data packets sent by the sender. 0 means no limit. | INT | 0 | [0, MaxValue). | Global & Session | Yes |
tunnel_buffer_size | The number of BUFFERs, the buffered sending queues from the sender side. The default value is 1. | INT | 1 | [0, MaxValue). | Global & Session | Yes |
pipeline_executor_use_thread_manager | The pipeline model uses a dynamic thread pool model. | BOOL | OFF | ON: Enables the pipeline model to use a dynamic thread pool. OFF: Disables the pipeline model from using a dynamic thread pool. | Global & Session | Yes |
enable_order_by_push_down | Enables/Disables the order by push-down feature. | BOOL | ON | ON: Enables the order by push-down feature. OFF: Disables the order by push-down feature. | Global & Session | Yes |
max_block_size | Sets the rows of data blocks passed in the pipeline execution engine. | INT | 65409 | [1, MaxValue). | Global & Session | Yes |
shuffle_after_join | Sets whether to scatter data into multiple pipelines after joins. | BOOL | ON | ON: Enables the scatter feature. OFF: Disables the scatter feature. | Global & Session | Yes |
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