Using pushdown predicates (deprecated)
To minimize the amount of data to be processed, enable pushdown predicates using cql3.pushdown.enable in the TBLPROPERTIES clause of a Hive query.
Hadoop is deprecated for use with DataStax Enterprise. DSE Hadoop and BYOH (Bring Your Own Hadoop) are deprecated. Hive is also deprecated and will be removed when Hadoop is removed.
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.