My question may be very broad but I really need to ask this. I am planning to use a Key Value NoSQL Database and I am completely new in NoSQL world. I was going through Wikipedia Page https://en.wikipedia.org/wiki/Key-value_database
我的问题可能非常广泛,但我真的需要问这个问题。我打算使用Key Value NoSQL数据库,我在NoSQL世界中是全新的。我正在浏览*页面https://en.wikipedia.org/wiki/Key-value_database
As per Wiki KV databases are categorized in 4 below categories.
根据Wiki,KV数据库分为以下4个类别。
KV – eventually consistent
KV – ordered
KV – RAM
KV – solid-state drive or rotating disk
I am not able to understand exact differences between them. If any one can explain it to me that would be great.
我无法理解它们之间的确切差异。如果任何人能向我解释这将是伟大的。
1 个解决方案
#1
1
This typology is interesting and maybe a little misleading. I can comment on some of these:
这种类型很有趣,可能有点误导。我可以评论其中的一些:
RAM - I've worked with Redis, so what I say will apply to that DB. Redis is designed to keep info in RAM, not on disc. Basically, if you turn it off the data is gone, so its more of a cache than a db. It Can be configured to preserve the data on disc, but its not designed to do so.
RAM - 我和Redis一起工作,所以我说的将适用于该数据库。 Redis旨在将信息保存在RAM中,而不是光盘上。基本上,如果你将其关闭,数据就会消失,所以它的缓存比db更多。它可以配置为保留光盘上的数据,但它不是为此而设计的。
eventually consistent - I've worked with Cassandra. EC means that read-operations are not guaranteed to provide the most up-to-date value. They will eventually return the most up-to-date, but not immediately following the update. In Cassandra, you specify which level of consistency you need - and this effect the speed at which you will be able to read/write. less consistency == faster (its a tradeoff). Unlike redis, cassandra saves to disc.
最终一致 - 我和卡桑德拉一起工作过。 EC意味着无法保证读取操作能够提供最新的值。他们最终将返回最新的,但不会立即返回更新。在Cassandra中,您可以指定所需的一致性级别 - 这会影响您能够读/写的速度。较低的一致性==更快(它的权衡)。与redis不同,cassandra可以保存到光盘。
solid-state drive or rotating disk - I've worked with couchbase. Couchbase saves to disc and is guaranteed to always be consistent (on read operations of keys, but not on views/indexes). so when you read a key from CB, you know its always the most up-to-date value. I think the name of this category is a little misleading. Other databases (like cassandra) also save to disc, so the name is a little off.
固态驱动器或旋转磁盘 - 我使用过couchbase。 Couchbase保存到光盘并保证始终保持一致(在读取操作键时,但不在视图/索引上)。因此,当您从CB读取密钥时,您知道它始终是最新的值。我认为这个类别的名称有点误导。其他数据库(如cassandra)也保存到光盘,所以名称有点偏。
hope this helps.
希望这可以帮助。
#1
1
This typology is interesting and maybe a little misleading. I can comment on some of these:
这种类型很有趣,可能有点误导。我可以评论其中的一些:
RAM - I've worked with Redis, so what I say will apply to that DB. Redis is designed to keep info in RAM, not on disc. Basically, if you turn it off the data is gone, so its more of a cache than a db. It Can be configured to preserve the data on disc, but its not designed to do so.
RAM - 我和Redis一起工作,所以我说的将适用于该数据库。 Redis旨在将信息保存在RAM中,而不是光盘上。基本上,如果你将其关闭,数据就会消失,所以它的缓存比db更多。它可以配置为保留光盘上的数据,但它不是为此而设计的。
eventually consistent - I've worked with Cassandra. EC means that read-operations are not guaranteed to provide the most up-to-date value. They will eventually return the most up-to-date, but not immediately following the update. In Cassandra, you specify which level of consistency you need - and this effect the speed at which you will be able to read/write. less consistency == faster (its a tradeoff). Unlike redis, cassandra saves to disc.
最终一致 - 我和卡桑德拉一起工作过。 EC意味着无法保证读取操作能够提供最新的值。他们最终将返回最新的,但不会立即返回更新。在Cassandra中,您可以指定所需的一致性级别 - 这会影响您能够读/写的速度。较低的一致性==更快(它的权衡)。与redis不同,cassandra可以保存到光盘。
solid-state drive or rotating disk - I've worked with couchbase. Couchbase saves to disc and is guaranteed to always be consistent (on read operations of keys, but not on views/indexes). so when you read a key from CB, you know its always the most up-to-date value. I think the name of this category is a little misleading. Other databases (like cassandra) also save to disc, so the name is a little off.
固态驱动器或旋转磁盘 - 我使用过couchbase。 Couchbase保存到光盘并保证始终保持一致(在读取操作键时,但不在视图/索引上)。因此,当您从CB读取密钥时,您知道它始终是最新的值。我认为这个类别的名称有点误导。其他数据库(如cassandra)也保存到光盘,所以名称有点偏。
hope this helps.
希望这可以帮助。