BROADCAST_BYTES_LIMIT Query Option

Sets the limit for the size of the broadcast input based on estimated size.

The Impala planner may in rare cases make a bad choice to broadcast a large table or intermediate result and encounter performance problems due to high memory pressure. Setting this limit will make the planner pick a partition based hash join instead of broadcast and avoid such performance problems.

Type: integer

Default:

The default value is 34359738368 (32 GB). A value of 0 causes the option to be ignored.

Examples:

  2. -- Change the limit to 16GB.
  3. set broadcast_bytes_limit=17179869184;
  5. -- Disable the BROADCAST_BYTES_LIMIT.
  6. set broadcast_bytes_limit=0;

Parent topic: Query Options for the SET Statement