A few days ago, the company planned to develop a large platform integrating various management functions, and let me be responsible for the development of test related services. For the first time, I was really busy as a dog. The project was finally approved last week and officially entered the development stage this week. The general requireme ...
Posted on Mon, 15 Jun 2020 23:18:31 -0400 by jsschmitt
quick get start
Official website document address: https://baomidou.gitee.io/mybatis-plus-doc/#/install
To use a third-party component:
1. Import corresponding dependencies
2. Study how dependencies are configured
3. How to write code
4. Improve the ability to expand techn ...
Posted on Sun, 14 Jun 2020 22:51:17 -0400 by nadman123
1. Why batch processing is needed
If there is a large number of sql to be executed in the database, and if it is sent one by one, the efficiency is too low, so you can add a large number of sql to a batch, send it to the database at one time, and then open the batch for execution.
2. Implementation ...
Posted on Sun, 14 Jun 2020 22:21:44 -0400 by happyme
When writing SQL, we often flexibly use some skills of SQL statement writing, which can greatly simplify the program logic. Reduce the number of interaction between the program and the database, which is conducive to the high availability of the database. At the same time, it can also appear that your SQL is very good, so that colleagues can se ...
Posted on Sun, 14 Jun 2020 04:44:28 -0400 by Hagbard
1.Spark performance tuning: use of checkPoint
Checkpoint means to establish checkpoints, similar to snapshots. For example, in spark computing, the computing process DAG is very long, and the server needs to complete the wh ...
Posted on Sun, 14 Jun 2020 00:48:31 -0400 by brokeDUstudent
Slow Query Log
Understanding slow queries
mysql's slow query is a type of log record provided by mysql that records statements whose execution time exceeds the set threshold.This time-out is configurable, and the default time-out is 10s, which is then written to the log.Then combined with explain to ...
Posted on Fri, 12 Jun 2020 22:13:07 -0400 by john9292
Cause: one day, my colleague's project connection pool burst
At first, I thought there was a long-running sql, but after checking the DB, I found that there was no such sql at all
Then I wonder if it is the calling of the third-party interface, which is suspended or not closed due to timeout. After ...
Posted on Fri, 12 Jun 2020 03:30:17 -0400 by ashbai
Today, let's practice how to optimize the SQL statements of two or more tables combined query.
Let's create two tables and prepare some data first
create table teacher(
tid int(4) primary key,
cid int(4) not null
insert teacher values(1,2);
insert teacher values(2,1);
insert teacher values( ...
Posted on Fri, 12 Jun 2020 02:24:32 -0400 by grumpy
Transaction processing of multiple data sources is a common topic. Transaction management across two data sources is also a category of distributed transactions. In the same JVM, transactions of multiple data sources are processed. The classic processing scheme is JTA (java standard transaction abstraction based on XA Protocol Modeling) ...
Posted on Thu, 11 Jun 2020 00:37:28 -0400 by ceruleansin
Universal Paging Hardcover Version
Ideas and Steps for Universal Paging
All required class structures and packages! [Insert picture description here] (Https://img-blog.csdnimg.cn/20200610235334613.png?X-oss-process=image/watermark, type_ZmFuZ3poZW5naGVpdGk, shadow_10, text_AHR0 ...
Posted on Wed, 10 Jun 2020 12:28:39 -0400 by _giles_