理学 数据库系统 释 relational algebra 关系代数 一种抽象的关系数据语言，它通过对关系的运算来表达查询。
algebra of relations 关系代数 relation algebra 关系代数 relational algebra 关系代数 relationship algebra 关系代数
数据库 数据库理论 释文 relational algebra 关系代数
- semisimple subalgebra
- semisimple subclass
- semisimple superalgebra
- semisimple symmetric space
- semisimple universal algebra
- semisimple variety
- semisimplicial
- semisimplicial chain complex
- semisimplicial complex
- semisimplicial group
- semisimplicial mapping
- semisimplicial resolution
- semisimplicial set
- semisimplicity
- semi-singular vector
- semi small
- semi-small
- semi-smooth
- semi-smooth equation
- semisolid
- semi-solid casting
- semi solid continuous casting
- semi-solid extrusion
- semi-solid forming
- semisolid medium