DB - Access Path Selection in a Relational Database Management System.pdf
In a high level query and data manipulation language such as SQL, requests are stated non-procedurally, without reference to access paths. This paper describes how System R chooses access paths for both simple (single relation) and complex queries (such as joins), given a user specification of desired data as a boolean expression of predicates. System R is an experimental database management system developed to carry ..
2022-07-12 20:05:16
192KB
数据库
优化器
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