A.JOIN

B.SELECT

C.UNION ALL

D.GROUP BY

A.Big data is the data processing of "fish in the pond" with a clear goal; the data processing of traditional database is to judge whether other kinds of "fish" exist or not through some "fish"

B.In big data, there is no unified data tool, that is, "No size fits all"; in traditional databases, in a specific business scenario, one tool can often solve a problem, that is, "One size fits all"

C.There are many types of data processed by big data, including structured, unstructured, and semi-structured data; the traditional database has a relatively single type of data, often structured data predominates.

D.The data scale of big data is very large, generally TB and PB are used as the data processing unit; the data size in traditional databases is generally small, and MB is often used as the data processing unit

A.Stream processing function

B.Distributed File System

C.Distributed memory computing engine

D.Unified scheduling of cluster resources

A.Resource recovery request queue priority

B.The queue with the lowest resource utilization has priority

C.The smallest queue level priority

D.Maximum queue level priority

A.Each partition is a directory

B.There can be more partitions or buckets under the partition

C.The number of partitions is fixed

D.The data table can be partitioned according to the value of a field