Using pushdown predicates
To minimize the amount of data to be processed, enable pushdown predicates using cql3.pushdown.enable in the TBLPROPERTIES clause of a Hive query.
Pushdown predicates resolve expressions as early as possible in the processing pipeline to minimize the amount of data to be processed. You enable pushdown predicates using the cql3.pushdown.enable property in the TBLPROPERTIES clause of a Hive query. True enables the feature and false (the default) disables it. Processing of operations on columns of the following types are affected by the setting:
Cassandra type | Hive type |
---|---|
UTF8Type | string |
AsciiType | string |
CounterColumnType | long |
DateType | timestamp |
LongType | long |
DoubleType | double |
FloatType | float |
BooleanType | boolean |
Int32Type | int |
Recommended usage
When the indexed row is small, enable pushdown predicates; otherwise, disable the feature to avoid a timeout exception or Out-Of-Memory (OOM) condition.
Pushdown predicate limitations
DataStax Enterprise supports pushdown predicates for indexes only. Primary keys are not supported.