HTAP database PostgreSQL scenarios and performance testing 26 - (OLTP) NOT IN, NOT EXISTS queries

Label PostgreSQL, HTAP, OLTP, OLAP, Scenario and Performance Testing background PostgreSQL is a database with a long history, which can be traced back to 1973. It was first awarded by the 2014 Computer Turing Prize winner and the originator of relational database. Michael_Stonebraker PostgreSQL has similar functions, performance, architectur ...

Posted on Tue, 18 Dec 2018 04:39:04 -0800 by webrajesh

mysql-8.0.12-winx64.zip version of MySQL Installation-Free Configuration Tutorial under windows

mysql-8.0.12-winx64.zip version of MySQL Installation-Free Configuration Tutorial under windows Step 1: Download this version of mysql file from the mysql official website Step 2: Unzip the file The third step is to analyze the file structure Step 4: Configuration Create a new data folder in the mysql root directory Create ...

Posted on Mon, 17 Dec 2018 04:57:04 -0800 by FireDrake

Python 3 full stack development - built-in function complement, reflection, metaclass, u str_, u del_, exec, type, u call_ method

I. Built-in Function Supplement 1. isinstance(obj,cls) checks whether obj is a cls-like object? class Foo(object):   pass obj = Foo() print(isinstance(obj, Foo)) #The result is True 2. issubclass(sub, super) checks whether the subclass is a derived class of the super class. class Foo(object):   pass class Ba ...

Posted on Mon, 17 Dec 2018 02:12:04 -0800 by Gorf

Dapper.net Nullable< DateTime> Solution of Exception Problems in Type Data Conversion

0x01 Running Environment dapper version 1.50.2 .net framework 4.5 0x02 Problem Description The entity object contains attributes such as DateTime?, DateTime, int, int?. When using the dapper method IDbConnect. Query <>() method, it prompts the System.InvalidOperationException exception, which is confirmed as the exception caused by D ...

Posted on Mon, 17 Dec 2018 02:00:04 -0800 by agent47

Python 3 Learning Notes 4 - Quote http://python 3-cookbook.readthedocs.io/zh_CN/latest/

2018-03-01 Data Structure and Algorithms (4) 1.16 Filter Sequence Elements The simplest way to filter sequence elements is to use list inference. For example: >>> mylist = [1, 4, -5, 10, -7, 2, 3, -1] >>> [n for n in mylist if n > 0] [1, 4, 10, 2, 3] >>> [n for n in mylist if n < 0] [-5, -7, -1] >>> ...

Posted on Mon, 17 Dec 2018 00:21:04 -0800 by Peredy

GoLanguage Learning Notes (8) Goang Operates Redis & Mysql & RabbitMQ

Add Golang Learning QQ Group to Learn Progress, Start a Family and Start a Business Job ^-^ Group Number: 96933959 Reids Installation Import go get github.com/garyburd/redigo/redis import "github.com/garyburd/redigo/redis" link github: https://github.com/antirez/redis Doc: http://godoc.org/github.com/garyburd/redigo/redis Redis comp ...

Posted on Sun, 16 Dec 2018 19:15:04 -0800 by jgmiddel

Remove the ready-to-use spring mvc and integrate mybatis (crud + paging plug-in) to operate mysql

1. Auto-encapsulation of 32-bit uuid for insertion data by annotations 2. Automatically encapsulating insertion date by annotation 3. Annotation realizes automatic update date of update data 4. Paging query auto-encapsulation returns the total number of qualified queries 5. Encapsulating data validation for arbitrary requests 6. Encapsulating ...

Posted on Sun, 16 Dec 2018 06:12:04 -0800 by smiley_kool

Rownum,Rowid,row_number() and oracle paging queries

1.rownum and rowid are pseudo columns, but they are fundamentally different. rownum assigns one to each row based on the results of sql queries Logical number, different sql will lead to different rownum, but rowid is physical structure, when every record Insert to the database, There will be a unique physical record. rowid can be said to ex ...

Posted on Sat, 15 Dec 2018 22:33:04 -0800 by cap2cap10

Twenty-fifth bullet of ASM translation series: When will my rebalance complete ASM advanced knowledge

Original text: When will my rebalance complete Author: Bane Radulovic Translator: Wei Xinghua is a senior technical expert of Waterloo Science and Technology. He mainly participates in the R&D and design of the company's integrated machine products, monitoring products, disaster tolerance products and DBaaS platform. He has worked for E ...

Posted on Sat, 15 Dec 2018 01:15:04 -0800 by UnsuitableBadger

Analysis of lock tables and unlock tables in MySQL

Analysis of lock tables and unlock tables in MySQL   The grammar functions of lock tables and unlock tables are provided in MySQL, which are not available in ORACLE and SQL Server databases. Believe that people who have just come into contact with MySQL want to have a detailed and in-depth understanding of this function. Next, try to fully anal ...

Posted on Fri, 14 Dec 2018 22:39:05 -0800 by mistcat