View and configure runtime parameters
What are runtime parameters?
Runtime parameters are variables that can be set at runtime to configure the behavior of RisingWave.
How to view runtime parameters?
You can use the SHOW ALL command to view the runtime parameters, their current settings, and some notes about these parameters.
SHOW ALL;
Name | Setting | Description
--------------------------------+-----------------+--------------------------------------
rw_implicit_flush | false | If `RW_IMPLICIT_FLUSH` is on, then every INSERT/UPDATE/DELETE statement will block until the entire dataflow is refreshed.
create_compaction_group_for_mv | false | If `CREATE_COMPACTION_GROUP_FOR_MV` is on, dedicated compaction groups will be created in MV creation.
query_mode | auto | A temporary config variable to force query running in either local or distributed mode. If the value is auto, the system will decide for you automatically.
extra_float_digits | 1 | Sets the number of digits displayed for floating-point values.
application_name | psql | Sets the application name to be reported in statistics and logs.
datestyle | | It is typically set by an application upon connection to the server.
rw_batch_enable_lookup_join | true | To enable the usage of lookup join instead of hash join when possible for local batch execution.
rw_batch_enable_sort_agg | true | To enable the usage of sort agg instead of hash join when order property is satisfied for batch execution.
max_split_range_gap | 8 | It's the max gap allowed to transform small range scan scan into multi point lookup.
search_path | "$user", public | Sets the order in which schemas are searched when an object (table, data type, function, etc.) is referenced by a simple name with no schema specified
visibility_mode | default | If `VISIBILITY_MODE` is all, we will support querying data without checkpoint.
query_epoch | 1 | Sets the historical epoch for querying data. If 0, querying latest data.
timezone | UTC | The session timezone. This will affect how timestamps are cast into timestamps with timezone.
streaming_parallelism | 0 | Sets the parallelism for streaming. If 0, use default value.
rw_streaming_enable_delta_join | false | Enable delta join in streaming queries.
rw_streaming_enable_bushy_join | true | Enable bushy join in streaming queries.
rw_enable_join_ordering | true | Enable join ordering for streaming and batch queries.
rw_enable_two_phase_agg | true | Enable two phase aggregation.
rw_force_two_phase_agg | false | Force two phase aggregation.
rw_enable_share_plan | true | Enable sharing of common sub-plans. This means that DAG structured query plans can be constructed, rather than only tree structured query plans.
intervalstyle | | It is typically set by an application upon connection to the server.
batch_parallelism | 0 | Sets the parallelism for batch. If 0, use default value.
server_version | 8.3.0 | The version of the server.
server_version_num | 80300 | The version number of the server.
rw_force_split_distinct_agg | false | Enable split the distinct aggregation.
How to configure runtime parameters?
You can use SET command or the set_config() function to change the setting of a runtime parameter.
The syntax of the SET command is:
SET parameter_name { TO | = } { value | 'value' };
Where parameter_name is the name of the parameter, and value or 'value' is the new value of the parameter.
For details about the set_config() function, see System administration functions.
