LARGE_AGG_MEM_THRESHOLD Query Option (Impala 4.4 or higher only)

The threshold for the query planner to determine whether memory estimation for an aggregation node is large or not. Together with AGG_MEM_CORRELATION_FACTOR, the planner will use this value to lower memory estimation for a large aggregation node.

Users can set this option value to 0.0 so the planner stays using the default NDV multiplication based-estimation. See AGG_MEM_CORRELATION_FACTOR documentation for more detail.

Type: integer

Default:

536870912 (512 MB)

Units: A numeric argument represents a size in bytes; you can also use a suffix of m or mb for megabytes, or g or gb for gigabytes. If you specify a value with unrecognized formats, subsequent queries fail with an error.

Added in: Impala 4.4

Related information:

AGG_MEM_CORRELATION_FACTOR Query Option (Impala 4.4 or higher only)