Slayer_Zhao的博客

非常好的练习资料：https://groverzhu.github.io/2019/01/21/数据库关系代数练习/#more SQL versus relational algebra Most of the databases nowadays arerelational databases. To make data available to users, the mos...

Using relational operators, specify the following queries on the COMPANY relational database schema shown below. 1. Retrieve the name (Fname, Lname) and address (Address) of all employees who work ...

1. Suppose that we have an ordered file with 30,000 records stored on a disk with block size 1,024 bytes. File records are of fixed size with record length 100 bytes. a) Find the number of block acce...