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内存数据库和嵌入式数据库的区别

[英]difference between in-memory and embedded databases

原文 2018-02-14 08:14:06 7 2 database/ in-memory-database/ embedded-database

I want to know if my understanding is correct:我想知道我的理解是否正确：

embedded : databases which are up if my application is up and are down if my application is down.嵌入式：如果我的应用程序启动，数据库就会启动，如果我的应用程序关闭，数据库就会关闭。 I am not referring the databases used in embedded space.我不是指嵌入式空间中使用的数据库。

in-memory : databases could be on any server;内存中：数据库可以在任何服务器上； irrespective of where my application is running.无论我的应用程序在哪里运行。 Just that, these uses main memory.只是，这些使用主要的 memory。

2 个解决方案

Full disclosure: I represent the vendor of eXtremeDB. 完全披露：我代表eXtremeDB的供应商。

Embedded databases have been around since at least the early 80's. 嵌入式数据库至少从80年代初开始就存在。 db_VISTA, c-tree, btrieve, Empress are some of the most common from back in the day. db_VISTA，c-tree，btrieve，Empress是当天最常见的一些。

'Embedded database' has nothing to do with embedded systems. “嵌入式数据库”与嵌入式系统无关。 It simply means a database management system that is delivered to the programmer as a set of object code libraries that are to be linked with the application object code into an executable program image. 它只是指一个数据库管理系统，它作为一组目标代码库提供给程序员，这些目标代码库将与应用程序目标代码链接成可执行程序映像。 In other words, the database functionality becomes part of the application itself, in the same address space. 换句话说，数据库功能在同一地址空间中成为应用程序本身的一部分。 Embedded databases were used primarily for line-of-business applications in the 80s and 90s. 嵌入式数据库主要用于80年代和90年代的业务线应用程序。 It wasn't until the late 90s and early 2000s that embedded systems began to migrate to 32-bit architectures in sufficient numbers that database systems could be considered to be commercially viable. 直到90年代末和21世纪初，嵌入式系统开始向足够数量的32位架构迁移，数据库系统才被认为具有商业可行性。 eXtremeDB was launched in 2001 as the first in-memory, embedded database system written explicitly for embedded systems. eXtremeDB于2001年推出，是第一个专为嵌入式系统编写的内存嵌入式数据库系统。 (8-bit and 16-bit systems do not have enough addressable memory to support a DBMS.) （8位和16位系统没有足够的可寻址内存来支持DBMS。）

An embedded database system can be either an in-memory database or persistent database (ie disk-based database). 嵌入式数据库系统可以是内存数据库或永久数据库（即基于磁盘的数据库）。

An in-memory database system can be an embedded database system, or it can be a client/server database system. 内存数据库系统可以是嵌入式数据库系统，也可以是客户端/服务器数据库系统。

A client/server database system can be an in-memory database system, or it can be a persistent database system. 客户端/服务器数据库系统可以是内存数据库系统，也可以是持久数据库系统。

As you can see, all the lines cross. 如您所见，所有线条交叉。 You can have 你可以有

client/server in-memory 客户端/服务器在内存中
client/server persistent 客户端/服务器持久化
embedded in-memory 嵌入式内存
embedded persistent 嵌入式持久化

And, you have have hybrids of all the above. 而且，你有上述所有的混合动力车。

DBMS Architecture :数据库管理系统架构：

Client-Server model: distributed structure where the DBMS resides on a server and client applications access the database; Client-Server model：分布式结构，DBMS 驻留在服务器上，客户端应用程序访问数据库； the database is said in server mode.数据库以服务器模式表示。
In-Process model: a monolithic structure where the DBMS and the application run in the same process; In-Process model：DBMS和应用程序在同一个进程中运行的单体结构； the database is said in embedded mode.数据库以嵌入式模式表示。

DBMS Storage :数据库管理系统存储：

in-memory: a database management system that employs memory as data storage (and disk as backup), the database is said in-memory mode. in-memory：采用memory作为数据存储（磁盘作为备份）的数据库管理系统，数据库称为in-memory模式。
on-disk or persistent: a database management system that employs disk as data storage (and memory as cache).磁盘上或持久性：使用磁盘作为数据存储（和 memory 作为缓存）的数据库管理系统。