nosql

问题 Write operations on Couchbase accept a parameter cas (create and set). Also the return result object of any non-data fetching query has cas property in it. I Googled a bit and couldn't find a good conceptual article about it. Could anyone tell me when to use CAS and how to do it? What should be the common work-flow of using CAS ? My guess is we need to fetch CAS for the first write operation and then pass it along with next write. Also we need to update it using result's CAS . Correct me if I

问题 What would be the equivalent of ERD for a NoSQL database such as MongoDB? 回答1: It looks like you asked a similar question on Quora. As mentioned there, the ERD is simply a mapping of the data you intend to store and the relations amongst that data. You can still make an ERD with MongoDB as you still want to track the data and the relations. The big difference is that MongoDB has no joins, so when you translate the ERD into an actual schema you'll have to make some specific decisions about

问题 What would be the equivalent of ERD for a NoSQL database such as MongoDB? 回答1: It looks like you asked a similar question on Quora. As mentioned there, the ERD is simply a mapping of the data you intend to store and the relations amongst that data. You can still make an ERD with MongoDB as you still want to track the data and the relations. The big difference is that MongoDB has no joins, so when you translate the ERD into an actual schema you'll have to make some specific decisions about

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 3 years ago . Target application is a medium-sized website built to support several hundred to several thousand users an hour, with an option to scale above that. Data model is rather simple, and caching potential is pretty high (~10:1 ratio of read to edit actions). What should be the

问题 What exactly is NoSQL? Is it database systems that only work with {key:value} pairs? As far as I know MemCache is one of such database systems, am I right? What other popular NoSQL databases are there and where exactly are they useful? Thanks, Boda Cydo. 回答1: From wikipedia: NoSQL is an umbrella term for a loosely defined class of non-relational data stores that break with a long history of relational databases and ACID guarantees. Data stores that fall under this term may not require fixed

问题 I'm looking at Amazon's DynamoDB as it looks like it takes away all of the hassle of maintaining and scaling your database server. I'm currently using MySQL, and maintaining and scaling the database is a complete headache. I've gone through the documentation and I'm having a hard time trying to wrap my head around how you would structure your data so it could be easily retrieved. I'm totally new to NoSQL and non-relational databases. From the Dynamo documentation it sounds like you can only

问题 I'm looking at Amazon's DynamoDB as it looks like it takes away all of the hassle of maintaining and scaling your database server. I'm currently using MySQL, and maintaining and scaling the database is a complete headache. I've gone through the documentation and I'm having a hard time trying to wrap my head around how you would structure your data so it could be easily retrieved. I'm totally new to NoSQL and non-relational databases. From the Dynamo documentation it sounds like you can only

问题 I am working on a project with a requirement of coming up with a generic dashboard where a users can do different kinds of grouping, filtering and drill down on different fields. For this we are looking for a search store that allows slice and dice of data. There would be multiple sources of data and would be storing it in the Search Store. There may be some pre-computation required on the source data which can be done by an intermediate components. I have looked through several blogs to

问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 6 years ago . I'm looking to use a NoSQL solution for my next project, which will be written in PHP. What choices do I have in terms of NoSQL

问题 I have a cluster of 3 ElasticSearch nodes running on AWS EC2. These nodes are setup using OpsWorks/Chef. My intent is to design this cluster to be very resilient and elastic (nodes can come in and out when needed). From everything I've read about ElasticSearch, it seems like no one recommends putting a load balancer in front of the cluster; instead, it seems like the recommendation is to do one of two things: Point your client at the URL/IP of one node, let ES do the load balancing for you