Home Database Mysql Tutorial mysql的静态表和动态表的区别,MyISAM和InnoDB的区别_MySQL

mysql的静态表和动态表的区别,MyISAM和InnoDB的区别_MySQL

Jun 01, 2016 pm 01:45 PM
dynamic surface

bitsCN.com

静态表字段长度固定,自动填充,读写速度很快,便于缓存和修复,但比较占硬盘,动态表是字段长度不固定,节省硬盘,但更复杂,容易产生碎片,速度慢,出问题后不容易重建。
3InnoDB和MyISAM是在使用MySQL最常用的两个表类型,各有优缺点,视具体应用而定。基本的差别为:MyISAM类型不支持事务处理等高级处理,而InnoDB类型支持。MyISAM类型的表强调的是性能,其执行数度比InnoDB类型更快,但是不提供事务支持,而InnoDB提供事务支持已经外部键等高级数据库功能。
MyIASM是IASM表的新版本,有如下扩展:
二进制层次的可移植性。
NULL列索引。
对变长行比ISAM表有更少的碎片。
支持大文件。
更好的索引压缩。
更好的键吗统计分布。
更好和更快的auto_increment处理。
1.MySQL最大的优势在于MyISAM引擎下的简单SELECT,INSERT和UPDATE快速操作
2.MyISAM类型的数据文件可以在不同操作系统中COPY,这点很重要,布署的时候方便点。
以下是一些细节和具体实现的差别:
1.InnoDB不支持FULLTEXT类型的索引。
2.InnoDB 中不保存表的具体行数,也就是说,执行select count(*) from table时,InnoDB要扫描一遍整个表来计算有多少行,但是MyISAM只要简单的读出保存好的行数即可。注意的是,当count(*)语句包含 where条件时,两种表的操作是一样的。

 

本文出自“耶稣”

bitsCN.com
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Fix: Windows 11's dynamic refresh rate doesn't work Fix: Windows 11's dynamic refresh rate doesn't work Apr 13, 2023 pm 08:52 PM

You can measure a screen's refresh rate by counting the number of times the image updates per second. DRR is a new feature included in Windows 11 that helps you save battery life while still providing a smoother display, but it's no surprise when it doesn't work properly. Screens with higher refresh rates are expected to become more common as more manufacturers announce plans to stop producing 60Hz monitors. This will result in smoother scrolling and better gaming, but it will come at the cost of reduced battery life. However, the dynamic refresh rate feature in this iteration of the OS is a nifty addition that can have a big impact on your overall experience. Read on as we discuss what to do if Windows 11’s dynamic refresh rate isn’t working

How to Hide Dynamic Island and Red Indicator in iPhone Screen Recording How to Hide Dynamic Island and Red Indicator in iPhone Screen Recording Apr 13, 2023 am 09:13 AM

On iPhone, Apple's screen recording feature records a video of what you're doing on the screen, which is useful if you want to capture gameplay, walk someone through a tutorial in an app, demonstrate a bug, or anything else. On older iPhones that have a notch at the top of the display, the notch is not visible in screen recording, as it should be. But on newer iPhones with the ‌Dynamic Island‌ cutout, such as the ‌iPhone 14 Pro‌ and ‌iPhone 14 Pro‌ Max, the ‌Dynamic Island‌ animation displays the red recording indicator, which causes the cutout to be visible in captured videos. this might

Convert VirtualBox fixed disk to dynamic disk and vice versa Convert VirtualBox fixed disk to dynamic disk and vice versa Mar 25, 2024 am 09:36 AM

When creating a virtual machine, you will be asked to select a disk type, you can select fixed disk or dynamic disk. What if you choose fixed disks and later realize you need dynamic disks, or vice versa? Good! You can convert one to the other. In this post, we will see how to convert VirtualBox fixed disk to dynamic disk and vice versa. A dynamic disk is a virtual hard disk that initially has a small size and grows in size as you store data in the virtual machine. Dynamic disks are very efficient at saving storage space because they only take up as much host storage space as needed. However, as disk capacity expands, your computer's performance may be slightly affected. Fixed disks and dynamic disks are commonly used in virtual machines

How to convert dynamic disk to basic disk on Windows 11 How to convert dynamic disk to basic disk on Windows 11 Sep 23, 2023 pm 11:33 PM

If you want to convert a dynamic disk to a basic disk in Windows 11, you should create a backup first as the process will erase all data in it. Why should you convert dynamic disk to basic disk in Windows 11? According to Microsoft, dynamic disks have been deprecated from Windows and their use is no longer recommended. Additionally, Windows Home Edition does not support dynamic disks, so you will not be able to access these logical drives. If you want to combine more disks into a larger volume, it is recommended to use Basic Disks or Storage Spaces. In this article, we will show you how to convert dynamic disk to basic disk on Windows 11 How to convert dynamic disk to basic disk in Windows 11? In the beginning

How to Get Live Tiles on the Desktop and Start Menu in Windows 11 How to Get Live Tiles on the Desktop and Start Menu in Windows 11 Apr 14, 2023 pm 05:07 PM

Imagine you are looking for something on your system but are not sure which application to open or select. This is where the Live Tiles feature comes into play. A live tile for any supported application can be added to the desktop or Windows system's Start menu, with its tiles changing frequently. LiveTiles make application widgets come alive in a very pleasing way. Not just for its appearance, but even for convenience. Suppose you are using whatsapp or facebook application on your system, wouldn't it be convenient if the number of notifications is displayed on the application icon? This is possible if any such supported app is added as a live tile. Let’s see how to do it in Windows

How to disable dynamic display of folders and files to prevent quick access in Windows 10 and 11? How to disable dynamic display of folders and files to prevent quick access in Windows 10 and 11? May 06, 2023 pm 04:58 PM

Microsoft introduced Quick Access in Windows 10 and retained the feature in the recently released Windows 11 operating system. Quick Access replaces the Favorites system in File Explorer. One of the core differences between the two features is that Quick Access adds a dynamic component to its list. Some folders appear permanently, while others appear based on usage. Fixed folders are displayed with a pin icon, while dynamic folders do not have such an icon. You can see a comparison between My Favorites and Quick Access here for more details. Quick Access is more powerful than Favorites, but dynamic folder lists add an element of clutter to it. Files that are useless or should not be highlighted in File Explorer may be displayed

How to use Dynamic Lock on Windows 11 How to use Dynamic Lock on Windows 11 Apr 13, 2023 pm 08:31 PM

What is dynamic locking on Windows 11? Dynamic Lock is a Windows 11 feature that locks your computer when a connected Bluetooth device (your phone or wearable) goes out of range. The Dynamic Lock feature automatically locks your PC even if you forget to use the Windows Key + L shortcut while walking away. Dynamic Lock works with any connected device with Bluetooth, but it's best to use a device with enough battery power and range, such as your phone. Once your device becomes inaccessible for 30 seconds, Windows will automatically lock the screen. Pair a Bluetooth device with Windows 11 For everything to work properly, you need to first

How to create a dynamic image carousel using HTML, CSS and jQuery How to create a dynamic image carousel using HTML, CSS and jQuery Oct 25, 2023 am 10:09 AM

How to use HTML, CSS and jQuery to create a dynamic image carousel. In website design and development, image carousel is a frequently used function for displaying multiple images or advertising banners. Through the combination of HTML, CSS and jQuery, we can achieve a dynamic image carousel effect, adding vitality and appeal to the website. This article will introduce how to use HTML, CSS and jQuery to create a simple dynamic image carousel, and provide specific code examples. Step 1: Set up HTML junction

See all articles