Drop Mapping#
The drop
mapping performs a projection of an input mapping by dropping a given list of columns.
Example#
mappings:
partial_facts:
kind: drop
input: facts
columns:
- id
- temperature
- wind_speed
Fields#
kind
(mandatory) (type: string):drop
broadcast
(optional) (type: boolean) (default: false): Hint for broadcasting the result of this mapping for map-side joins.cache
(optional) (type: string) (default: NONE): Cache mode for the results of this mapping. Supported values areNONE
- Disables caching of teh results of this mappingDISK_ONLY
- Caches the results on diskMEMORY_ONLY
- Caches the results in memory. If not enough memory is available, records will be uncached.MEMORY_ONLY_SER
- Caches the results in memory in a serialized format. If not enough memory is available, records will be uncached.MEMORY_AND_DISK
- Caches the results first in memory and then spills to disk.MEMORY_AND_DISK_SER
- Caches the results first in memory in a serialized format and then spills to disk.
input
(mandatory) (type: string): Specifies the name of the input mapping to be filtered.columns
(mandatory) (type: list:string): Specifies the list of columns to be removed from the input.filter
(optional) (type: string) (default: empty): An optional SQL filter expression that is applied after projection.
Outputs#
main
- the only output of the mapping