ClickHouse是俄罗斯的Yandex于2016年开源的列式存储数据库(DBMS),使用C++语言编写,主要用于在线分析处理查询(OLAP),能够使用SQL查询实时生成分析数据报告。 OLAP(On-Line Analytical Processing)翻译为联机分析处理,专注于分析处理,从对数据库操作来看,OLAP是对数据的查询; OLTP(on-line transaction processing)翻译为联机...
三、 DBMS_XPLAN包 除了结合explain plan命令外... explain;来获取执行计划,这种方法虽然也执行了sql语句,但是执行计划不一定是真实的。 引用一个经典的例子(不是我做的)来证明:autotrace on和explain plan的结果是使用index SQL优化 第二章 执行计划 calls)可以方便看到。 3 EXPLAIN PLAN 当某个性能SQL死掉,...
Explain with examples what is meant by lossy decomposition and how this problem can be avoided in DBMS. Explain the steps involved in location-based (geo fencing) marketing. What are some qualities of good pseudocode? How world you define functional programming? 1. What is an extreme po...
(a) What is a multivalued dependency in DBMS? (b) Give an example. In java, under what circumstances should an interface be used instead of an abstract class? What is an example of ambiguous grammar? The point of this exercise is to define multiple classes via inheritance. The classes ...
system in a non-concurrent force system, the lines of action of the forces do not intersect at a single point. this type of force system requires additional considerations such as moments and couples to determine the overall effect on the object. an example of a non-concurrent force system ...
ClickHouse是俄罗斯的Yandex于2016年开源的列式存储数据库(DBMS),使用C++语言编写,主要用于在线分析处理查询(OLAP),能够使用SQL查询实时生成分析数据报告。 OLAP(On-Line Analytical Processing)翻译为联机分析处理,专注于分析处理,从对数据库操作来看,OLAP是对数据的查询; OLTP(on-line transaction processing)翻译为联机...
Describe at least three functions that a Database Management System (DBMS) performs to help create an accurate and consistent view of data throughout an enterprise. Briefly discuss three strengths from the VIA Classification of Strengths and give examples of how they apply ...