Classification, creation and deletion of MySQL indexes

1, Index overview 1. Concept of index An index is a sorted list in which the index value and the physical address of the row containing the data containing the value are stored (similar to the linked list of C language, which points to the memory address of the data record through a pointer).After using the index, you can not scan the who ...

Posted on Sat, 23 Oct 2021 22:26:08 -0400 by don_s

Python learns the basics of 5 tuples and common functions

Tuple concept Tuple: a = (1, 23) List: a= [1,23] Create and access tuples Python tuples are similar to lists, except that tuples cannot be modified after they are created, which is similar to strings. Tuples, like lists, are indexed and sliced with integers. Tuple subscript: 0 – (n-1) You can create tuples with parentheses (), or with ...

Posted on Tue, 28 Sep 2021 15:53:00 -0400 by GooberDLX