Tag:data type

  • Data sharing in multithreading and multiprocessing in Python


    Previously, when writing multithreading and multiprocessing, because they usually complete their own tasks, and there is not much contact between each sub thread or sub process before. If I need to communicate, I will use the queue or database to complete it. But recently, when I wrote some code for multithreading and multiprocessing, I found […]

  • What is redis? It’s enough to read this one


    introduction At the beginning of the development of web application, relational database was widely concerned and applied at that time, the reason is that web site access and concurrency were not high and interaction was less. Later, with the increase of access, web sites using relational databases began to have some performance bottlenecks, and the […]

  • JavaScript variable, data type, basic instance details [variable, string, array, object, etc.]


    This article describes the JavaScript variables, data type basis. For your reference, the details are as follows: In this note, I record the basic knowledge of variables and data types. Because they are related, they are recorded together How to declare variables Variable declaration uses the VaR keyword. Here are some examples of variable declaration: […]

  • Getting started with Amazon dynamodb 1: configuration (local) and python examples


    What is Amazon dynamodb Amazon dynamodb is a fully managed NoSQL database service that provides fast and predictable performance and enables seamless scaling. With dynamodb, you can avoid the administrative burden of operating and expanding distributed databases, so you don’t have to worry about hardware presetting, setup and configuration, replication, software patching, or cluster expansion. […]

  • C ා basic knowledge series – 1 data type


    Common data types The types of C ාValue type、reference typeThere are two types.Instances of value types are stored in the stack, and reference types place a pointer to a piece of content in the heap.C ා has built in several data types for us to use: Key words abbreviation Full name of the corresponding class […]

  • Self taught Python by Xiaobai (4) Python data type


    Series articles: It is very suitable for Xiaobai’s Python learning route Self taught Python by Xiaobai (1) Python tutorial Xiaobai self taught python (2) construction of Python development environment Xiaobai taught himself python (3) basic syntax of Python Self taught Python by Xiaobai (4) Python data type Self taught Python by Xiaobai (5) Python operator […]

  • C language notes (2): data type (basic data type), type conversion (automatic conversion, cast)


    Welcome to my official account, “old notes”, or to visit my personal blog. www.yuxiaoshao.cn Can QQ exchange learning 1316677086 or join my group exchange: 901648700 share resources, exchange learning data type Can add QQ group together to learn C language 984775301Data types are a wide range of systems used to declare variables or functions of […]

  • Notes on MySQL optimization


    Take notes and keep them updated. Optimization direction dba SQL optimization analysis Index optimization Optimizing database objects Optimize the data type of the table Table splitting (horizontal, vertical) Anti paradigm Use intermediate table Optimize MySQL server MySQL memory management optimization Log mechanism and optimization Adjusting MySQL concurrency parameters Application optimization Database connection pool Use cache […]

  • SQL Server union all result sum function causes precision loss


    Usage scenarios: In the multi-dimensional summary of data, it is necessary to merge the data of different data types and different data precision into a table, and the accuracy of relevant calculation will be lost.   Troubleshooting: After segmented investigation, the cause of the loss was found, and the sum function caused the precision loss […]

  • Sql:SQL Server CREATE SEQUENCE statement


    —Auto growth jumps to 1001 https://stackoverflow.com/questions/17587094/identity-column-value-suddenly-jumps-to-1001-in-sql-server –1. Use sequence https://docs.microsoft.com/zh-cn/sql/t-sql/statements/create-sequence-transact-sql?view=sql-server-ver15 –2. Register the startup parameter – t272 for SQL server IF EXISTS(SELECT * FROM sys.sequences WHERE name = N’Id_Sequence’) DROP SEQUENCE Id_Sequence; GO CREATE SEQUENCE Id_Sequence AS INT Start with 1 — count from 1 Increment by 1 — how many at a time MinValue […]

  • JavaScript series: 1. Hand tearing the depth copy in JS


    This article first appeared in nuggets, address JavaScript series: 1. Hand tear JS deep copy preface Interviewer: how to write a deep copy?Applicant: JSON.parse ( JSON.stringify (object))Interviewer: what are the advantages and disadvantages?Applicant: cannot serialize function, ignore undefinedInterviewer: is there any other way? How to solve circular references?Candidate: for loop… 1、 Data type 1. Basic […]

  • Redis — common data structure


    About redis Redis is an open source (BSD licensed) in memory data structure server that can be used as a database, cache and message queuing agent It supports string, hash table, list, collection, ordered collection, bitmap, hyperloglogs and other data types Built in replication, Lua script, LRU recall, transaction and different levels of disk persistence […]