+ +

BUFFER_POOL_LIMIT Query Option

+ + + +
+ +

+ + Defines a limit on the amount of memory that a query can allocate from the + internal buffer pool. The value for this limit applies to the memory on each host, + not the aggregate memory across the cluster. Typically not changed by users, except + during diagnosis of out-of-memory errors during queries. +

+ +

+ Type: integer +

+ + + +

+ Default: +

+

+ The default setting for this option is the lower of 80% of the + MEM_LIMIT setting, or the MEM_LIMIT + setting minus 100 MB. +

+ +

+ Added in: Impala 2.10.0 +

+ +

+ Usage notes: +

+

+ If queries encounter out-of-memory errors, consider decreasing the + BUFFER_POOL_LIMIT setting to less than 80% of the + MEM_LIMIT setting. +

+ +

+ Examples: +

+ +

+-- Set an absolute value.
+set buffer_pool_limit=8GB;
+
+-- Set a relative value based on the MEM_LIMIT setting.
+set buffer_pool_limit=80%;
+
+
+ +

+ Related information: +

+

+ DEFAULT_SPILLABLE_BUFFER_SIZE Query Option, + MAX_ROW_SIZE Query Option, + MIN_SPILLABLE_BUFFER_SIZE Query Option, + Scalability Considerations for Impala +

+ +
+