sample

swordfish.function.sample()

Must be used in a where clause. Take a random sample of a number of partitions in a partitioned table.

Suppose the database has N partitions. If 0<size<1, then take int(N*size) partitions. If size is a positive integer, then take size partitions.

参数:

• partitionCol (Constant) -- A partitioning column.

• size (Constant) -- A positive floating number or integer.