Beginners, Oracle database on the Internet to see said in order to improve the efficiency to avoid a cartesian product, but is how to improve the efficiency? Consult the CSDN,, thank you.

CodePudding user response:

Cartesian product will be in the table if not connected condition produced when two 100 lines of table joins is 1 w record three 100 lines of table is 100 w in the real life such a connection will not have much practical significance

CodePudding user response:

reference 1st floor weixin_38847048 response:

cartesian product will be in the table if not connected condition produced when two 100 lines of table joins is 1 w record three 100 lines of table is 100 w in the real life such a connection will not have much practical significance

That if you use the equivalent connection is equivalent to remove the cartesian product is?

CodePudding user response:

Suggest the original poster to learn first "cartesian product" this concept,

CodePudding user response:

The

reference 3 floor wmxcn2000 response:

suggest the original poster to learn first "cartesian product" this concept,

Good good, I knew more about again