• SDS of redis data structure


    SDS(simple dynamic string), simple dynamic string. S and it’s called hacking string. Where hack is stored is the length of the string and the remaining space in SDS. The implementation of SDS insds.cIn the middle. C language string uses a character array of length N + 1 to represent the string of length N, and […]

  • Oracle creates users quickly, imp / exp imports and exports DMP files


    1. First of all, we can use the administrator user to log in to Oracle as SYSDBA sqlplus username/password as sysdba; Then I can create users create user username identified by password; 3. After creating the user, we can modify the user’s password alter user username identified by password; 4. In general, we don’t use […]

  • Spark simple wordcount instance


    docker docker pull sequenceiq/spark:1.6.0 docker run -it -p 8088:8088 -p 8042:8042 -p 4040:4040 -h sandbox sequenceiq/spark:1.6.0 bash maven <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!– SPARK –> <dependency> <groupId>org.apache.spark</groupId> <artifactId>spark-core_${scala.binary.version}</artifactId> <version>${spark.version}</version> <exclusions> <exclusion> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> </exclusion> <exclusion> <groupId>log4j</groupId> <artifactId>log4j</artifactId> </exclusion> </exclusions> </dependency> <!– SPARK STREAMING –> <dependency> <groupId>org.apache.spark</groupId> <artifactId>spark-streaming_${scala.binary.version}</artifactId> <version>${spark.version}</version> <exclusions> <exclusion> […]

  • Talking about virtual memory


    Hello, I’m Liang Xu. Familiar with the computer’s small partners know, we often say the host three pieces are the motherboard, CPU, memory, visible memory in the role of the computer host is not the same, like DIY host of small partners to understand these three pieces is better. Small partners who have written programs […]

  • This is a short essay


    The little fish is more lovely than the little fish   describe People are more angry than people; fish are more difficult to die than fish. Xiaoyu recently took part in a “loveliness contest” to compare the loveliness of each fish. The fish in the competition are arranged in a row from left to right, […]

  • On the C language macro definition skills: ‘#’and’ # ‘


    On the C language macro definition skills: ‘#’and’ # ‘ ‘#’ and ‘#’ ‘#’ and ‘#’ are two preprocessing operators, which can only be used during preprocessing. In the macro definition with parameters, ‘#’Operator should be followed by a parameter, which the preprocessor converts to a string. ‘##’Operator is called token join operator. For example, […]

  • Hands on how to configure Vue’s eslint


    1. Install eslint npm install –save-dev eslint 2. New.eslintrc.jsFile configuration eslint If you install it globally, eslint can also be usedeslint –initTo configure files automatically The default configuration is as follows: (eslint — init automatically generated) module.exports = { “extends”: “eslint:recommended”, “parserOptions”: { “ecmaVersion”: 5, “sourceType”: “module” }, “rules”: { } }; Let’s test itConfigure […]

  • From the actual project, what is the design space


    preface: I have been engaged in small and micro enterprise information work for more than 10 years, and my own small studio has developed one project after another with members like running water. In more than ten years of experience, I have developed a set of ASP.NET The framework of the project. This set of […]

  • Oracle automatic collection task statistics, SQL tuning


    –View auto collection task status SELECT CLIENT_NAME,STATUS FROM DBA_AUTOTASK_CLIENT; SELECT CLIENT_NAME, STATUS FROM DBA_AUTOTASK_CLIENT WHERE CLIENT_NAME = ‘auto optimizer stats collection’; –Turn off auto optimizer stats collection BEGIN DBMS_AUTO_TASK_ADMIN.DISABLE(CLIENT_NAME => ‘auto optimizer stats collection’, OPERATION => NULL, WINDOW_NAME => NULL); END; / –Shut down SQL optimizer SQL Tuning Advisor (STA) BEGIN DBMS_AUTO_TASK_ADMIN.DISABLE(CLIENT_NAME => ‘sql tuning […]

  • Shell learning notes – Basics


    Shell learning notes – Basics Learning course LearnShell Learning content Hello,World Knowledge points Beginning of shell file #!/bin/bash See all bash programs running ps | grep $$ See the bash interpreter which bash Output Hello, world #!/bin/bash echo “Hello,world!” variable Define variable: use equal sign = (can’t have blank) PRICE_PER_APPLE=5 MyFirstLetters=ABC greeting=’Hello world!’ Escape character: […]

  • Building Jenkins combat system based on docker in Linux system environment


    About CI, CD & CD Ci > continuous integration: continuous integration CD > continuous delivery: continuous delivery CD > continuous deployment: continuous deployment Jenkins Jenkins is an open source CI & CD software for automating various tasks, including building, testing and deploying software. It supports various running modes, such as system package, docker or an […]

  • Template language in Django


    Template itself has its own language and syntax to handle simple data display Common grammar Judgment instruction{% if condition%}… {% ENDIF%}{% if condition%}… {% elif condition%}… {% ENDIF%}{% if condition%}… {% elif condition%}… {% else%}… {% ENDIF%} {% if a in b %}…{%endif%} Cyclic instruction {%for %} …{%endfor} {% froloop.counter% }The counter used to display […]