問題文
A retail team reads a directory of half a million small record files. Before the aggregation starts, the monitoring screen shows a job that reads every file once, and only then the real work begins. No column names or types were given to the reader. What is that first job?
選択肢
- Reading a directory of records without a declared schema makes the reader perform one additional sampling pass over the input first.
- Reading a directory of records without a declared schema makes the reader perform one unavoidable caching cycle over the input first.
- Reading a directory of records without a declared schema makes the reader perform one external sorting round over the input first.
- Reading a directory of records without a declared schema makes the reader perform one immediate write back over the input first.