• Forced benchmarking of relational database with mongodb and elasticsearch


    Structural benchmarking RDBMS MongoDB Elasticsearch Table Collection Index Row Document Document Column Field Field Schema Schema Mapping SQL DSL Noun interpretation RDBMS RDBMS is the relational database management system, which organizes data into related rows and columns. The computer software for managing RDBMS is the relational database management system. The commonly used database software includes […]

  • Mongodb learning


    Mongodb is a database based on distributed file storage. Written in C + +. It aims to provide scalable high-performance data storage solutions for web applications. Here are the advantages of distributed: Reliability (fault tolerance): An important advantage of distributed computing system is reliability. The system crash of one server does not affect the rest […]

  • Mall integrates mongodb to realize document operation


    Spring boot actual e-commerce project Mall (20k + star) address: https://github.com/macrozheng/mall abstract This paper mainly explains the process of integrating mongodb with mall, taking the implementation of adding, deleting and querying commodity browsing records in mongodb as an example. Introduction to project use framework Mongodb Mongodb is a database system built for rapid development of […]

  • Research on the principle of ThreadPoolExecutor in Java


    I. Introduction Thread pool mainly solves two problems: on the one hand, when executing a large number of asynchronous tasks, thread pool can provide better performance, because using thread pool can reduce the call cost of each task (because thread pool threads can be reused). On the other hand, thread pool provides a means of […]

  • Redis + mongodb, a must for job hopping, often asks 80 interview questions


    Preface The recruitment season known as “golden nine silver ten” has already started, and the peak period of job hopping has also arrived. This article is mainly about the strategy of redis + mongodb knowledge points, hoping to help you. There are many contents, so we are ready for patience and melon seed mineral water. […]

  • Data processing of players in online games


    background The most important data in online games is the data generated by players in the process of games. It can be simply divided into two categories: archived data Process record data The first type of data mainly includes the basic information of similar characters, knapsack, skills, tasks, as well as the Kingdom, map, alliance […]

  • Must mongodb scan the whole table to locate oplog?


    Mongodb oplog (similar to MySQL binlog) records all the modification operations of the database, in addition to the primary and secondary synchronization; oplog can play many tricks, such as Full backup + incremental backup of all oplog can realize the function of mongodb recovery to any point in time Through oplog, in addition to synchronization […]

  • Mongodb quick start notes (1): how to install mongodb in Windows


    Mongodb is a database based on distributed file storage. Written in C + +. It aims to provide scalable high-performance data storage solutions for web applications. Mongodb is a product between relational database and non relational database. It has the most abundant functions and is the most like relational database. Mongodb download address:http://www.mongodb.org/downloads 1. Install […]

  • Ten years of data analysis experience, summed up the best use of these three types of tools


    When it comes to data analysis tools, I believe you are familiar with them, but many people have a doubt? With so many data analysis tools, what’s the difference between them? Which is better? Which is stronger? Which should I learn? Although this question is a bit conventional, but it is very important, I have […]

  • Djongo: Django and mongodb connectors


    Mongodb is used as the back-end database in Django project, and the ORM framework of Django is not changed. Realize the addition and modification of files in mongodb database by Django user management program. usage 1.pip install djongo 2. Add the following code to setting.py under Django project: DATABASES ={ ‘default’:{ ‘ENGINE:’djongo’, ‘NAME’:’your-db-name’, } } […]

  • Using Django to manage the existing database


    In most projects, there are always some almost invariable CRUD operations. It is boring to write these codes, but it is also one of the essential functions of the whole system. We also faced similar problems in the previous project. Although a relatively complete management background has been realized and code reuse has been achieved […]

  • Mongodb start warning: soft rlimits too low


    When mongodb was started today, I didn’t pay attention to it before. Today, I found out that it was warning again. I want to make it whole. Here are the alarms 2019-09-05T12:00:55.271+0800 I CONTROL [initandlisten] 2019-09-05T12:00:55.271+0800 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is ‘always’. 2019-09-05T12:00:55.271+0800 I CONTROL [initandlisten] ** We suggest setting it to ‘never’ […]