Question:- How to script NoSQL DB configuration?
Answer:- You may find that you want to build the same NoSQL DB configuration repeatedly for testing purposes. The Admin CLI commands can be scripted in several ways.Many uses of the Admin CLI are simple commands, such as java -jar kvstore.jar makebootconfig to initially configure a StorageNode, shown above. These are as amenable to scripting as any other UNIX commands and will not be discussed further here.The interactive commands available in java -jar kvstore.jar runadmin, among which are those used to create and execute plans, can be scripted in two ways. You can create a file containing the sequence of commands that you want to run, and run them in a batch using java -jar kvstore.jar runadmin load -file
Question:- What is the difference between NoSQL & Mysql DBs’?
Answer:- NoSQL databases are becoming a major part of the database landscape today, and with their handful of advantages, they can be a real game changer in the enterprise arena. However, NoSQL isn’t ripe yet, and professionals in the industry need to approach it with caution. This is because it lacks the maturity that SQL databases like MySQL offer. If your application doesn’t fall into the category of the likes of Google, Yahoo, Facebook or Wikipedia, you should reconsider your options for using NoSQL and stick with MySQL instead. Not only is there a major skills gap with finding NoSQL professionals, but issues like analytics, performance reporting and migration also need to be considered.
Question:- Explain Oracle NoSQL database?
Answer:- The Oracle NoSQL Database is a distributed key-value database. It is designed to provide highly reliable, scalable and available data storage across a configurable set of systems that function as storage nodes.Data is stored as key-value pairs, which are written to particular storage node(s), based on the hashed value of the primary key. Storage nodes are replicated to ensure high availability, rapid failover in the event of a node failure and optimal load balancing of queries. Customer applications are written using an easy-to-use Java/C API to read and write data. Oracle NoSQL Driver links with the customer application, providing access to the data via appropriate storage node for the requested key. A web based console as well as command line interface is available for easy administration of the cluster.
Question:- When should I use a NoSQL database instead of a relational database?
Answer:- A relational database enforces ACID. So, you will have schema based transaction oriented data stores. It’s proven and suitable for 99% of the real world applications. You can practically do anything with relational databases.But, there are limitations on speed and scaling when it comes to massive high availability data stores. For example, Google and Amazon have terabytes of data stored in big data centers. Querying and inserting is not per formant in these scenarios because of the blocking/schema/transaction nature of the RDBMs. That’s the reason they have implemented their own databases (actually, key-value stores) for massive performance gain and scalability.NoSQL databases have been around for a long time – just the term is new. Some examples are graph, object, column, XML and document databases.
Question:- What is CouchDB?
Answer:- CouchDB is a database that completely embraces the web. Store your data with JSON documents. Access your documents and query your indexes with your web browser, via HTTP. Index, combine, and transform your documents with JavaScript. CouchDB works well with modern web and mobile apps. You can even serve web apps directly out of CouchDB. And you can distribute your data, or your apps, efficiently using CouchDB’s incremental replication. CouchDB supports master-master setups with automatic conflict detection. CouchDB comes with a suite of features, such as on-the-fly document transformation and real-time change notifications, that makes web app development a breeze. It even comes with an easy to use web administration console. You guessed it, served up directly out of CouchDB! We care a lot about distributed scaling. CouchDB is highly available and partition tolerant, but is also eventually consistent. And we care a lot about your data. CouchDB has a fault-tolerant storage engine that puts the safety of your data first.
Question:- What Language is CouchDB Written in?
Answer:- Erlang, a concurrent, functional programming language with an emphasis on fault tolerance. Early work on CouchDB was started in C++ but was replaced by Erlang OTP platform. Erlang has so far proven an excellent match for this project. CouchDB’s default view server uses Mozilla’s Spidermonkey JavaScript library which is written in C. It also supports easy integration of view servers written in any language.
Question:- Why Does CouchDB Not Use Mnesia?
Answer:- Several reasons: • The first is a storage limitation of 2 gig per file. • The second is that it requires a validation and fixup cycle after a crash or power failure, so even if the size limitation is lifted, the fixup time on large files is prohibitive. • Mnesia replication is suitable for clustering, but not disconnected, distributed edits. Most of the “cool” features of Mnesia aren’t really useful for CouchDB. • Also Mnesia isn’t really a general-purpose, large scale database. It works best as a configuration type database, the type where the data isn’t central to the function of the application, but is necessary for the normal operation of it. Think things like network routers, HTTP proxies and LDAP directories, things that need to be updated, configured and reconfigured often, but that configuration data is rarely very large.
Question:- How do you compare MongoDB, CouchDB and CouchBase?
Answer:- MongoDB and CouchDB are document-oriented databases. MongoDB and CouchDB are the most typical representative of the open-source NoSQL database. They have nothing in common other than being stored in the document outside. MongoDB and CouchDB, the data model interface, object storage, and replication methods have many differences.
Question:- How is PouchDB different from CouchDB?
Answer:- PouchDB is also a CouchDB client, and you should be able to switch between a local database or an online CouchDB instance without changing any of your application’s code. However, there are some minor differences to note: • View Collation – CouchDB uses ICU to order keys in a view query; in PouchDB they are ASCII ordered. • View Offset – CouchDB returns an offset property in the view results. In PouchDB, offset just mirrors the skip parameter rather than returning a true offset.
Question:- So is CouchDB now going to written in Java?
Answer:- Erlang is a great fit for CouchDB and I have absolutely no plans to move the project off its Erlang base. IBM/Apache’s only concerns are we remove license incompatible 3rd party source code bundled with the project, a fundamental requirement for any Apache project. So some things may have to replaced in the source code (possibly Mozilla Spidermonkey), but the core Erlang code stays. An important goal is to keep interfaces in CouchDB simple enough that creating compatible implementations on other platforms is feasible. CouchDB has already inspired the database projects RDDB and Basura. Like SQL databases, I think CouchDB needs competition and a ecosystem to be viable long term. So Java or C++ versions might be created and I would be delighted to see them, but it likely won’t be me who does it.
Question:- What does IBM’s involvement mean for CouchDB and the community?
Answer:- The main consequences of IBM’s involvement are: – The code is now being apache licensed, instead of GPL. – Damien is going to be contributing much more time!
Question:- Mention the main features of CouchDB?
Answer:- • JSON Documents – Everything stored in CouchDB boils down to a JSON document. • RESTful Interface – From creation to replication to data insertion, every management and data task in CouchDB can be done via HTTP. • N-Master Replication – You can make use of an unlimited amount of ‘masters’, making for some very interesting replication topologies. • Built for Offline – CouchDB can replicate to devices (like Android phones) that can go offline and handle data sync for you when the device is back online. • Replication Filters – You can filter precisely the data you wish to replicate to different nodes.
Question:- What is the use of CouchDB?
Answer:- CouchDB allows you to write a client side application that talks directly to the Couch without the need for a server side middle layer, significantly reducing development time. With CouchDB, you can easily handle demand by adding more replication nodes with ease. CouchDB allows you to replicate the database to your client and with filters you could even replicate that specific user’s data. Having the database stored locally means your client side application can run with almost no latency. CouchDB will handle the replication to the cloud for you. Your users could access their invoices on their mobile phone and make changes with no noticeable latency, all whilst being offline. When a connection is present and usable, CouchDB will automatically replicate those changes to your cloud CouchDB. CouchDB is a database designed to run on the internet of today for today’s desktop-like applications and the connected devices through which we access the internet.