Principles of index creation and design

1. Declaration and use of index 1.1 classification of index MySQL indexes include general index, unique index, full-text index, single column index, multi column index and spatial index. In terms of functional logic, there are four kinds of indexes: ordinary index, unique index, primary key index and full-text index. According to the physical i ...

Posted by micbox on Thu, 10 Mar 2022 17:32:18 +0100

PG Database Source-SysCache Partial Matching Mechanism

The catcache code is located at src/backend/utils/cache/catcache.c, which contains links and operations to initialize SysCache structures and pointer relationships between data structures. Finding tuples in CatCache There are two ways to find tuples in a CatCache: exactly matching the SearchCatCache and partially matching the SearchCatcac ...

Posted by hanhao on Thu, 10 Mar 2022 19:05:13 +0100

0 basic society on the dynamic planning of editing distance (with C + + source code)

catalogue Question 1: judgment subsequence Question 2: different subsequences Question 3: deletion of two strings Question 4: editing distance Today, we continue to study the algorithm problems of dynamic programming, which are a series of algorithm problems about finding editing distance. Let's make a summary. I'll copy these problems t ...

Posted by social_experiment on Thu, 10 Mar 2022 21:51:02 +0100

Deadlock and deadlock detection

1, What is a deadlock For example, if thread a occupies resource 1, thread b occupies resource 2, thread b needs resource 1 and thread a needs resource 2, a deadlock will occur In the deadlock solution, log and gdb debugging can be used when the number of threads is small log and gdb cannot be used to solve the problem of too many thre ...

Posted by pentinat on Thu, 10 Mar 2022 17:25:19 +0100

spring source code - @ Configuration and @ ComponentScan parsing principle

I believe everyone is familiar with the core refresh method started by the spring container. The invokebeanfactoryprocessors method is a very important method for processing beanFactory, @ Component @Bean and so on. 1 @Configuration 2 @ComponentScan("org.springframework.context.annotation") 3 public class MyComponentScan { 4 @ComponentSca ...

Posted by flientje on Thu, 10 Mar 2022 17:14:06 +0100

Several sorting methods of arrays

Quick sort Quick sorting embodies the idea of divide and conquer. Determine the final position of a number each time, place it in the correct position, and then quickly sort the arrays at both ends in the same way through recursion. It should be noted that when using quick sort, the decision number needs to be taken randomly, which is called ...

Posted by ferronrsmith on Thu, 10 Mar 2022 17:33:18 +0100