Related Documentation Download this Manual
PDF (US Ltr) - 0.6Mb
PDF (A4) - 0.6Mb


HeatWave User Guide  /  Reference  /  System Variables

11.7 System Variables

HeatWave maintains several variables that configure its operation. Variables are set when the HeatWave cluster is enabled. Most HeatWave variable settings are managed by OCI and cannot be modified directly.

  • rapid_bootstrap

    Command-Line Format --rapid-bootstrap[={OFF|ON|IDLE}]
    Introduced 8.0.17
    System Variable rapid_bootstrap
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value OFF
    Valid Values

    IDLE

    ON

    The setting for this variable is managed by OCI and cannot be modified directly. Defines the HeatWave cluster bootstrap state. States include:

    • OFF

      The HeatWave cluster is not bootstrapped (not initialized).

    • IDLE

      The HeatWave cluster is idle (stopped).

    • ON

      The HeatWave cluster is bootstrapped (started).

  • rapid_dmem_size

    Command-Line Format --rapid-dmem-size=#
    Introduced 8.0.17
    System Variable rapid_dmem_size
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value 2048
    Minimum Value 512
    Maximum Value 2097152

    The setting for this variable is managed by OCI and cannot be modified directly. Specifies the amount of DMEM available on each core of each node, in bytes.

  • rapid_memory_heap_size

    Command-Line Format --rapid-memory-heap-size=#
    Introduced 8.0.17
    System Variable rapid_memory_heap_size
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value unlimited
    Minimum Value 67108864
    Maximum Value unlimited

    The setting for this variable is managed by OCI and cannot be modified directly. Defines the amount of memory available for the HeatWave plugin, in bytes. Ensures that HeatWave does not use more memory than is allocated to it.

  • rapid_execution_strategy

    Command-Line Format --rapid_execution_strategy[={MIN_RUNTIME|MIN_MEM_CONSUMPTION}]
    Introduced 8.0.22
    System Variable rapid_execution_strategy
    Scope Session
    Dynamic No
    SET_VAR Hint Applies No
    Type Enumeration
    Default Value MIN_RUNTIME
    Valid Values

    MIN_RUNTIME

    MIN_MEM_CONSUMPTION

    Specifies the query execution strategy to use. Minimum runtime (MIN_RUNTIME) or minimum memory consumption (MIN_MEM_CONSUMPTION).

    HeatWave optimizes for network usage rather than memory. If you encounter out of memory errors when running a query, try running the query with the MIN_MEM_CONSUMPTION strategy by setting by setting rapid_execution_strategy prior to executing the query:

    SET SESSION rapid_execution_strategy = MIN_MEM_CONSUMPTION;

    See Chapter 10, Troubleshooting.

  • rapid_stats_cache_max_entries

    Command-Line Format --rapid-stats-cache-max-entries=#
    Introduced 8.0.25
    System Variable rapid_stats_cache_max_entries
    Scope Global
    Dynamic Yes
    SET_VAR Hint Applies No
    Type Integer
    Default Value 65536
    Minimum Value 0
    Maximum Value 1048576

    The setting for this variable is managed by OCI and cannot be modified directly. Specifies the maximum number of entries in the statistics cache.

    The number of entries permitted in the statistics cache by default is 65536, which is enough to store statistics for 4000 to 5000 unique queries of medium complexity.

    For more information, see Auto Query Plan Improvement.